Method and device for transmitting uplink control signal in wireless communication system

ABSTRACT

A method for transmitting an uplink control signal of a terminal in a wireless communication system and a terminal using the method are provided. The method comprises the steps of: setting a first physical uplink control channel (PUCCH) resource for a first antenna port; setting a second PUCCH resource for a second antenna port; and transmitting a same uplink control signal through the first and second antenna ports by using the first and second PUCCH resources, wherein the first and second PUCCH resources are orthogonal to each other.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to wireless communication, and moreparticularly, to a method and a device for transmitting an uplinkcontrol signal in a wireless communication system.

Related Art

A frequency source is in a saturated state based on the current, andvarious technologies have been partially used in a wide frequency band.To this reason, in order to satisfy a higher demand quantity of the datatransmission rate, as a method for ensuring a wide bandwidth, carrieraggregation (CA) has been introduced, which is a concept in which eachof distributed bands is designed to satisfy basic requirements capableof operating an independent system and a plurality of bands is bound asone system. In this case, a band or a carrier which can be independentlyoperated is defined as a component carrier (CC).

In recent communication standard, for example, standard such as 3rdgeneration partnership project (3GPP), long term evolution-advanced(LTE-A), or 802.16m, it is considered that the bandwidth is continuouslyextended up to 20 MHz or more. In this case, the wideband is supportedby aggregating one or more component carriers. For example, when onecomponent carrier corresponds to a bandwidth of 5 MHz, a bandwidth ofmaximum 20 MHz is supported by aggregating four carriers. As such, asystem of supporting carrier aggregation is called a carrier aggregationsystem.

Meanwhile, the wireless communication system may use a transmitdiversity when transmitting the uplink control signal. The transmitdiversity means a technique of transmitting the same signal by usingdifferent antenna ports. One type of transmit diversity includes aspatially orthogonal resource transmit diversity (SORTD). The SORTD is atransmit diversity technique of transmitting the same signalsimultaneously by assigning and using spatially orthogonal resources todifferent antenna ports. The transmit diversity may be also applied to acarrier aggregation system.

In the case of applying the transmit diversity to transmit the uplinkcontrol signal, which resource is assigned to a second antenna port,that is, an additional antenna port other than an antenna port (referredto as a first antenna port) used in single antenna port transmissionbecomes a problem. Particularly, when anacknowledgement/not-acknowledgement (ACK/NACK) signal representingacknowledgement for the data is transmitted by using the SORTD, whichresource is applied to the second antenna port may become a problem.

SUMMARY OF THE INVENTION

The present invention has been made in an effort to a method and adevice for transmitting an uplink control signal in a wirelesscommunication system.

In one aspect, a method for transmitting an uplink control signal ofuser equipment in a wireless communication system is provided. Themethod comprises: configuring a first physical uplink control channel(PUCCH) resource for a first antenna port, configuring a second PUCCHresource for a second antenna port and transmitting the same uplinkcontrol signal through the first antenna port and the second antennaport by using the first PUCCH resource and the second PUCCH resource,wherein the first PUCCH resource and the second PUCCH resource areorthogonal to each other.

In another aspect, a method for transmitting an uplink control signal ofuser equipment in a wireless communication system is provided. Themethod comprises: configuring an explicit physical uplink controlchannel (PUCCH) resource and transmitting an uplink control signal byusing the explicit PUCCH resource, wherein the explicit PUCCH resourceis used to transmit an acknowledgement/not-acknowledgement (ACK/NACK)for a physical downlink shard channel (PDSCH) without a correspondingphysical downlink control channel (PDCCH) or an ACK/NACK for a PDSCHwithout a corresponding enhanced-PDCCH (e-PDCCH).

In still another aspect, a user equipment (UE) is provided. The UEcomprises: a radio frequency (RF) unit which transmits or receives aradio signal and a processor connected with the RF unit, wherein theprocessor configures a first physical uplink control channel (PUCCH)resource for a first antenna port, configures a second PUCCH resourcefor a second antenna port, and transmits the same uplink control signalthrough the first antenna port and the second antenna port by using thefirst PUCCH resource and the second PUCCH resource, in which the firstPUCCH resource and the second PUCCH resource are orthogonal to eachother.

According to the present invention, it is possible to efficientlyperform ACK/NACK transmission for a plurality of cells in a carrieraggregation system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a downlink radio frame structure in 3rd generationpartnership project (3GPP) long term evolution (LTE).

FIG. 2 illustrates a structure of a time division duplex (TDD) radioframe in 3GPP LTE.

FIG. 3 illustrates one example of a resource grid for one downlink slot.

FIG. 4 illustrates a downlink subframe.

FIG. 5 illustrates a structure of an uplink subframe.

FIG. 6 illustrates a channel structure of a PUCCH format 2/2a/2b for oneslot in a normal CP.

FIG. 7 illustrates a PUCCH format 1a/1b for one slot in the normal CP.

FIG. 8 exemplifies a channel structure of the PUCCH format 3.

FIG. 9 exemplifies the synchronous HARQ.

FIG. 10 illustrates a comparative example of a single carrier system inthe related art and a carrier aggregation system.

FIG. 11 illustrates an example of implicit PUCCH resource mapping insingle antenna port transmission.

FIG. 12 illustrates an example of a method of determining the PUCCHresource used in two antenna ports, when the SORTD is applied as thePUCCH transmit diversity scheme.

FIG. 13 illustrates another example of a method of determining the PUCCHresource used in two antenna ports, when the SORTD is applied as thePUCCH transmit diversity scheme.

FIG. 14 illustrates a method of transmitting the ACK/NACK by using theSORTD according to the fifth embodiment.

FIG. 15 illustrates an example of e-PDCCH assignment.

FIG. 16 illustrates an example of a method of configuring the offset bythe ARI.

FIG. 17 illustrates an example of determining the resource for thesecond antenna port.

FIG. 18 illustrates an example of resource mapping for the secondantenna port in the case where the PUCCH transmit diversity is appliedand the SORTD is applied as the technique thereof.

FIG. 19 illustrates an example of subframe bundled scheduling.

FIG. 20 illustrates an example of cross subframe scheduling.

FIG. 21 illustrates a configuration of a base station and user equipmentaccording to the embodiment of the present invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

A user equipment (UE) may be fixed or mobile, and may be referred to asanother terminology, such as a mobile station (MS), a mobile terminal(MT), a user terminal (UT), a subscriber station (SS), a wirelessdevice, a personal digital assistant (PDA), a wireless modem, a handhelddevice, etc.

A base station (BS) is generally a fixed station that communicates withthe UE and may be referred to as another terminology, such as an evolvednode-B (eNB), a base transceiver system (BTS), an access point, etc.

FIG. 1 shows a downlink radio frame structure in 3rd generationpartnership project (3GPP) long term evolution (LTE). The section 4 of3GPP TS 36.211 V8.7.0 (2009-05) “Evolved Universal Terrestrial RadioAccess (E-UTRA); Physical Channels and Modulation (Release 8)” may beincorporated herein by reference for time division duplex (TDD).

A radio frame includes 10 subframes indexed with 0 to 9. One subframeincludes 2 consecutive slots. A time required for transmitting onesubframe is defined as a transmission time interval (TTI). For example,one subframe may have a length of 1 millisecond (ms), and one slot mayhave a length of 0.5 ms.

FIG. 2 illustrates a structure of a time division duplex (TDD) radioframe in 3GPP LTE.

In the TDD radio frame, a downlink (DL) subframe, an uplink (UL)subframe, and a specific subframe may coexit.

Table 1 illustrates one example of a UL-DL configuration of the radioframe.

TABLE 1 Uplink- Switch- downlink point Subframe index configurationperiodicity 0 1 2 3 4 5 6 7 8 9 0 5 ms D S U U U D S U U U 1 5 ms D S UU D D S U U D 2 5 ms D S U D D D S U D D 3 10 ms  D S U U U D D D D D 410 ms  D S U U D D D D D D 5 10 ms  D S U D D D D D D D 6 5 ms D S U U UD S U U D

‘D’ represents a DL subframe, ‘U’ represents a UL subframe, and ‘S’represents a special subframe. When user equipment receives the UL-DLconfiguration from a base station, the user equipment may determinewhich subframe is the DL subframe or the UL subframe according to theconfiguration of the radio frame.

A subframe having an index #1 and an index #6 is called a specialsubframe, and includes a downlink pilot time slot (DwPTS), a guardperiod (GP), and an uplink pilot time slot (UpPTS). The DwPTS is used inthe UE for initial cell search, synchronization, or channel estimation.The UpPTS is used in the BS for channel estimation and uplinktransmission synchronization of the UE. The GP is a period for removinginterference which occurs in an uplink due to a multi-path delay of adownlink signal between the uplink and a downlink.

FIG. 3 illustrates one example of a resource grid for one downlink slot.

Referring to FIG. 3, the downlink slot may include a plurality of OFDMsymbols in a time domain and N_(RB) resource blocks (RBs) in a frequencydomain. The resource block as the resource allocation unit includes oneslot in the time domain and a plurality of contiguous subcarriers in thefrequency domain. The number N_(RB) of resource blocks included in thedownlink slot is subordinate to a downlink bandwidth set in a cell. Forexample, in an LTE system, N_(RB) may be any one of 6 to 110. Thestructure of an uplink slot may also be the same as that of the downlinkslot.

Each element on the resource grid is called a resource element (RE). Theresource element on the resource grid may be identified by a pair ofindexes (k,l) in the slot. Herein, k (k=0, . . . , N_(RB)×12−1)represents a subcarrier index in the frequency domain, and l (l=0, . . ., 6) represents an OFDM symbol index in the time domain.

In FIG. 3, it is exemplarily described that one resource block isconstituted by 7 OFDM symbols in the time domain and 12 subcarriers inthe frequency domain and thus includes 7×12 resource elements, but thenumber of the OFDM symbols and the number of the subcarriers in theresource block are not limited thereto. The number of the OFDM symbolsand the number of the subcarriers may be variously changed depending onthe length of the CP, frequency spacing, and the like. As the number ofsubcarriers in one OFDM symbol, one of 128, 256, 512, 1024, 1536, and2048 may be selected and used.

FIG. 4 illustrates a downlink subframe.

A downlink (DL) subframe is divided into a control region and a dataregion in the time domain. The control region includes maximum fourprevious OFDM symbols of a first slot in the subframe, but the number ofOFDM symbols included in the control region may be changed. A physicaldownlink control channel (PDCCH) and other control channel are allocatedto the control region and a PDSCH is allocated to the data region.

As disclosed in the 3GPP TS 36.211 V10.2.0, in 3GPP LTE/LTE-A, aphysical control channel includes a physical downlink control channel(PDCCH), a physical control format indicator channel (PCFICH), and aphysical hybrid-ARQ indicator channel (PHICH).

The PCFICH transmitted in a first OFDM symbol of the subframe transportsa control format indicator (CFI) regarding the number (that is, the sizeof the control region) of OFDM symbols used to transmit control channelsin the subframe. The wireless device first receives the CFI on thePCFICH and thereafter, monitors the PDCCH.

Unlike the PDCCH, the PCFICH is transmitted through a fixed PCFICHresource of the subframe without using blind decoding.

The PHICH transports a positive-acknowledgment(ACK)/negative-acknowledgement (NACK) signal for an uplink (UL) hybridautomatic repeat request (HARQ). An ACK/NACK signal for uplink (UL) dataon the PUSCH transmitted by the wireless device is transmitted on thePHICH.

A physical broadcast channel (PBCH) is transmitted in four previous OFDMsymbols of a second slot of the first subframe of the radio frame. ThePBCH transports system information required for the wireless device tocommunicate with the base station, and the system informationtransmitted through the PBCH is called a master information block (MIB).As compared therewith, system information transmitted on the PDSCHinstructed by the PDCCH is called a system information block (SIB).

Control information transmitted through the PDCCH is called downlinkcontrol information (DCI). The DCI may include resource allocation (alsoreferred to as downlink (DL) grant) of the PDSCH, resource allocation(also referred to as uplink (UL) grant) of the PUSCH, a set oftransmission power control commands for individual UEs in apredetermined UE group, and/or activation of a voice over Internetprotocol (VoIP).

In 3GPP LTE/LTE-A, transmission of the DL transmission block isperformed in a pair of the PDCCH and the PDSCH. Transmission of the DLtransmission block is performed in a pair of the PDCCH and the PDSCH.For example, the wireless device receives the DL transmission block onthe PDSCH instructed by the PDCCH. The wireless device monitors thePDCCH in the DL subframe to receive the DL resource allocation on thePDCCH. The wireless device receives the DL transmission block on thePDSCH where the DL resource allocation is indicated.

The base station determines a PDCCH format according to a DCI to betransmitted to the wireless device and then adds a cyclic redundancycheck (CRC) to the DCI, and masks a unique identifier (referred to as aradio network temporary identifier (RNTI)) to the CRC according to anowner or a usage of the PDCCH.

In the case of a PDCCH for a specific wireless device, a uniqueidentifier of the wireless device, for example, a cell-RNTI (C-RNTI) maybe masked on the CRC. Alternatively, in the case of a PDCCH for a pagingmessage, a paging indication identifier, for example, a paging-RNTI(P-RNTI) may be masked on the CRC. In the case of a PDCCH for systeminformation, a system information-RNTI (SI-RNTI) may be masked on theCRC. A random access-RNTI (RA-RNTI) may be masked on the CRC in order toindicate the random access response which is a response to transmissionof a random access preamble. In order to instruct a transmit powercontrol (TPC) command for a plurality of wireless devices, the TPC-RNTImay be on the CRC. In the PDCCH for semi-persistent scheduling (SPS),the SPS-C-RNTI may be masked on the CRC.

When the C-RNTI is used, the PDCCH transports control information(referred to as UE-specific control information) for the correspondingspecific wireless device, and when another RNTI is used, the PDCCHtransports common control information which all or a plurality ofwireless devices in the cell receive.

Coded data is generated by encoding the DCI added with the CRC. Theencoding includes channel encoding and rate matching. The coded data ismodulated to generate modulated symbols. The modulated symbols aremapped on a physical RE.

The control region in the subframe includes a plurality of controlchannel elements (CCEs). The CCE as a logical allocation unit used toprovide the coding rate to the PDCCH depending on a state of a radiochannel corresponds to a plurality of resource element groups (REGs).The REG includes a plurality of resource elements. A format of the PDCCHand the bit number of available PDCCH are determined according to acorrelation of the number of CCEs and the coding rate provided by theCCEs.

One REG includes four REs, and one CCE includes nine REGs. In order toconfigure one PDCCH, {1, 2, 4, 8} CCEs may be used, and each element of{1, 2, 4, 8} is referred to as a CCE aggregation level.

The number of CCEs used for the transmission of the PDDCH is determinedaccording to a channel state. For example, in the wireless device havinga good downlink channel state, one CCE may be used for the transmissionof the PDDCH. For example, in the wireless device having a poor downlinkchannel state, eighth CCEs may be used for the transmission of thePDDCH.

A control channel configured by one or more CCEs performs interleavingof a REG unit, and is mapped on the physical resource after a cyclicshift based on a cell identifier (ID) is performed.

FIG. 5 illustrates a structure of an uplink subframe.

Referring to FIG. 5, an uplink subframe may be divided into a controlregion and a data region in a frequency domain. A physical uplinkcontrol channel (PUCCH) for transmitting uplink control information isallocated to the control region. A physical uplink shared channel(PUSCH) for transmitting data (in some cases, control information may betransmitted together) is allocated to the data region. According to aconfiguration, the UE may simultaneously transmit the PUCCH and thePUSCH and may transmit only one of the PUCCH and the PUSCH.

A PUCCH for one UE is allocated to a RB pair in the subframe. The RBsthat belong to the RB pair occupy different subcarriers in first andsecond slots, respectively. A frequency occupied by the RBs that belongto the RB pair allocated to the PUCCH is changed based on a slotboundary. This means that the RB pair allocated to the PUCCH isfrequency-hopped on the slot boundary. The UE transmits the uplinkcontrol information through different subcarriers with time to acquire afrequency diversity gain.

On the PUCCH, a hybrid automatic repeat request (HARQ) acknowledgement(ACK)/non-acknowledgement (NACK), channel state information (CSI)indicating a downlink channel state, for example, a channel qualityindicator (CQI), a precoding matrix index (PMI), a precoding typeindicator (PTI), a rank indication (RI), and the like may betransmitted.

The CQI provides information on link adaptive parameters which can besupported by the UE for a predetermined time. The CQI may indicate adata rate which may be supported by the DL channel by considering acharacteristic of the UE receiver, a signal to interference plus noiseratio (SINR), and the like. The base station may determine modulation(QPSK, 16-QAM, 64-QAM, and the like) to be applied to the DL channel anda coding rate by using the CQI. The CQI may be generated by variousmethods. For example, the various methods include a method of quantizingand feed-backing the channel state as it is, a method of calculating andfeed-backing a signal to interference plus noise ratio (SINR), a methodof notifying a state which is actually applied to the channel such as amodulation coding scheme (MCS), and the like. When the CQI is generatedbased on the MCS, the MCS includes a modulation scheme, a coding scheme,and a coding rate according to the coding scheme, and the like.

The PMI provides information on a precoding matrix in precoding based ona code book. The PMI is associated with the multiple input multipleoutput (MIMO). The feed-backing of the PMI in the MIMO may be called aclosed loop MIMO.

The RI is information on a rank (that is, the number of layers)recommended by the UE. That is, the RI represents the number ofindependent streams used in spatial multiplexing. The RI may be fed-backonly in the case where the UE operates in an MIMO mode using the spatialmultiplexing. The RI is always associated with one or more CQIfeed-backs. That is, the fed-back CQI is calculated by assuming apredetermined RI value. Since the rank of the channel is generallychanged slower than the CQI, the RI is fed-back less than the number ofCQIs. A transmission period of the RI may be a multiple of the CQI/PMItransmission period. The RI is provided in the entire system band, and afrequency-selective RI feedback is not supported.

A PUCCH transports various types of control information according to aformat. PUCCH format 1 transports a scheduling request (SR). In thiscase, an on-off keying (OOK) scheme may be applied. PUCCH format 1atransports an acknowledgement/non-acknowledgment (ACK/NACK) modulated bya binary phase shift keying (BPSK) scheme with respect to one codeword.PUCCH format 1b transports an ACK/NACK modulated by a quadrature phaseshift keying (QPSK) scheme with respect to two codewords. PUCCH format 2transports a channel quality indicator (CQI) modulated by the QPSKscheme. The PUCCH formats 2a and 2b transport the CQI and the ACK/NACK.

The PUCCH formats may be divided according to the modulation scheme andthe number of bits in the subframe. Table 2 illustrates a modulationscheme according to the PUCCH format and the number of bits in thesubframe.

TABLE 2 PUCCH format modulation scheme bit number per subframe 1 N/A N/A1a BPSK 1 1b QPSK 2 2 QPSK 20 2a QPSK + BPSK 22 2b QPSK + QPSK 22

All PUCCH formats use a cyclic shift (CS) of a sequence in each OFDMsymbol. The cyclically shifted sequence is generated by cyclicallyshifting a base sequence by a specific CS amount. The specific CS amountis indicated by a CS index.

An example of a base sequence ru(n) is defined by Equation 1 below.

r _(u)(n)=e ^(jb(n)π/4)  [Equation 1]

In Equation 1, u denotes a root index, and n denotes a component indexin the range of 0≦N≦1, where N is a length of the base sequence. b(n) isdefined in the section 5.5 of 3GPP TS 36.211 V8.7.0.

A length of a sequence is equal to the number of elements included inthe sequence. u can be determined by a cell identifier (ID), a slotnumber in a radio frame, etc. When it is assumed that the base sequenceis mapped to one RB in a frequency domain, the length N of the basesequence is 12 since one RB includes 12 subcarriers. A different basesequence is defined according to a different root index.

The base sequence r(n) can be cyclically shifted by Equation 2 below togenerate a cyclically shifted sequence r(n, Ics).

$\begin{matrix}{{{r\left( {n,I_{cs}} \right)} = {{r(n)} \cdot {\exp \left( \frac{j\; 2\pi \; I_{cs}n}{N} \right)}}},{0 \leq I_{cs} \leq {N - 1}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

In Equation 2, Ics denotes a CS index indicating a CS amount(0≦I_(cs)≦N−1).

Hereinafter, the available CS of the base sequence denotes a CS indexthat can be derived from the base sequence according to a CS interval.For example, if the base sequence has a length of 12 and the CS intervalis 1, the total number of available CS indices of the base sequence is12. Alternatively, if the base sequence has a length of 12 and the CSinterval is 2, the total number of available CS indices of the basesequence is 6.

FIG. 6 illustrates a channel structure of a PUCCH format 2/2a/2b for oneslot in a normal CP. As described above, the PUCCH format 2/2a/2b isused to transmit the CQI.

Referring to FIG. 6, single carrier-frequency division multiple access(SC-FDMA) symbols 1 and 5 are used for a demodulation reference symbol(DM RS) which is an uplink reference signal in the normal CP. In anextended CP, an SC-FDMA symbol 3 is used for the DM RS.

10 CQI information bits are channel-coded at for example, 1/2 rate tobecome 20 coded bits. In the channel coding, a reed-muller (RM) code maybe used. In addition, the information bits are scrambled (similarly asPUSCH data being scrambled with a gold sequence having a length of 31)and thereafter, mapped with QPSK constellation, and as a result, a QPSKmodulation symbol is generated (d₀ to d₄ in slot 0). Each QPSKmodulation symbol is modulated by a cyclic shift of a basic RS sequencehaving a length of 12 and OFDM-modulated and thereafter, transmitted ineach of 10 SC-FDMA symbols in the subframe. 12 periodic shifts uniformlyseparated from each other allow 12 different user equipments to beorthogonally multiplexed in the same PUCCH resource block. As a DM RSsequence applied to the SC-FDMA symbols 1 and 5, the basic RS sequencehaving the length of 12 may be used.

FIG. 7 illustrates a PUCCH format 1a/1b for one slot in the normal CP.An uplink reference signal is transmitted from third to fifth SC-FDMAsymbols. In FIG. 7, w₀, w₁, w₂, and w₃ may be modulated in the timedomain after inverse fast Fourier transform (IFFT) modulation ormodulated in the frequency domain before the IFFT modulation.

One slot includes 7 OFDM symbols. Three OFDM symbols are used asreference signal (RS) OFDM symbols for a reference signal. Four OFDMsymbols are used as data OFDM symbols for an ACK/NACK signal.

In the PUCCH format 1b, a modulation symbol d(0) is generated bymodulating a 2-bit ACK/NACK signal based on quadrature phase shiftkeying (QPSK).

A CS index Ics may vary depending on a slot number ns in a radio frameand/or a symbol index 1 in a slot.

In the normal CP, there are four data OFDM symbols for transmission ofan ACK/NACK signal in one slot. It is assumed that CS indices mapped tothe respective data OFDM symbols are denoted by I_(cs0), I_(cs1),I_(cs2), and I_(cs3).

The modulation symbol d(0) is spread to a cyclically shifted sequencer(n,I_(cs)). When a one-dimensionally spread sequence mapped to an(i+1)th OFDM symbol in a subframe is denoted by m(i), it can beexpressed as follows.

{m(0),m(1),m(2),m(3)}={d(0)r(n,I _(cs0)),d(0)r(n,I _(cs1)),d(0)r(n,I_(cs2)),d(0)r(n,I _(cs3))}

In order to increase UE capacity, the one-dimensionally spread sequencecan be spread by using an orthogonal sequence. An orthogonal sequencew_(i)(k) (where i is a sequence index, 0≦k≦K−1) having a spreadingfactor K=4 uses the following sequence.

TABLE 3 Index (i) ┌w_(i)(0), w_(i)(1), w_(i)(2), w_(i)(3)┐ 0 [+1, +1,+1, +1] 1 [+1, −1, +1, −1] 2 [+1, −1, −1, +1]

An orthogonal sequence w_(i)(k) (where i is a sequence index, 0≦k≦K−1)having a spreading factor K=3 uses the following sequence.

TABLE 4 Index (i) [w_(i)(0), w_(i)(1), w_(i)(2)] 0 [+1, +1, +1] 1 [+1,e^(j2π/3), e^(j4π/3)] 2 [+1, e^(j4π/3), e^(j2π/3)]

A different spreading factor can be used for each slot.

Therefore, when any orthogonal sequence index i is given, atwo-dimensionally spread sequences {s(0), s(1), s(2), s(3)} can beexpressed as follows.

{s(0),s(1),s(2),s(3)}={w _(i)(0)m(0),w _(i)(1)m(1),w _(i)(2)m(2),w_(i)(3)m(3)}

The two-dimensionally spread sequences {s(0), s(1), s(2), s(3)} aresubjected to inverse fast Fourier transform (IFFT) and thereafter aretransmitted in corresponding OFDM symbols. Accordingly, an ACK/NACKsignal is transmitted on a PUCCH.

A reference signal for the PUCCH format 1b is also transmitted bycyclically shifting the base sequence r(n) and then by spreading it bythe use of an orthogonal sequence. When CS indices mapped to three RSOFDM symbols are denoted by I_(cs4), I_(cs5), and I_(cs6), threecyclically shifted sequences r(n,I_(cs4)), r(n,I_(cs5)), andr(n,I_(cs6)) can be obtained. The three cyclically shifted sequences arespread by the use of an orthogonal sequence w_(RS,i)(k) having aspreading factor K=3.

An orthogonal sequence index i, a CS index I_(cs), and a resource blockindex m are parameters required to configure the PUCCH, and are alsoresources used to identify the PUCCH (or UE). If the number of availablecyclic shifts is 12 and the number of available orthogonal sequenceindices is 3, PUCCHs for 36 UEs in total can be multiplexed with oneresource block.

In the 3GPP LTE, a resource index n⁽¹⁾ _(PUCCH) is defined in order forthe UE to obtain the three parameters for configuring the PUCCH. Theresource index n⁽¹⁾ _(PUCCH) is defined to n_(CCE)+N⁽¹⁾ _(PUCCH), wheren_(CCE) is an index of a first CCE used for transmission ofcorresponding DCI (i.e., DL resource allocation used to receive DL datamapped to an ACK/NACK signal), and N⁽¹⁾ _(PUCCH) is a parameter reportedby a BS to the UE by using a higher-layer message.

Time, frequency, and code resources used for transmission of theACK/NACK signal are referred to as ACK/NACK resources or PUCCHresources. As described above, an index of the ACK/NACK resourcerequired to transmit the ACK/NACK signal on the PUCCH (referred to as anACK/NACK resource index or a PUCCH index) can be expressed with at leastany one of an orthogonal sequence index i, a CS index I_(cs), a resourceblock index m, and an index for obtaining the three indices. TheACK/NACK resource may include at least one of an orthogonal sequence, acyclic shift, a resource block, and a combination thereof.

Meanwhile, in LTE-A, a PUCCH format 3 is introduced in order to transmitthe UL control information (for example, the ACK/NACK and the SR) of amaximum of 21 bits (represent the bit number before channel coding asinformation bits and a maximum of 22 bits when the SR is included). ThePUCCH format 3 uses the QPSK as the modulation scheme, and a bit numberwhich is transmittable in the subframe is 48 bits (representing a bitnumber transmitted after the information bits are channel-coded).

The PUCCH format 3 performs block spreading based transmission. That is,a modulated symbol sequence that modulates a multi-bit ACK/NACK by usinga block spreading code is spread and thereafter, transmitted in the timedomain.

FIG. 8 exemplifies a channel structure of the PUCCH format 3.

Referring to FIG. 8, a modulated symbol sequence {d1, d2, . . . } isspread in the time domain by applying the block spreading code. Theblock spreading code may be an orthogonal cover code (OCC). Herein, themodulated symbol sequence may be a sequence of the modulated symbols inwhich the ACK/NACK information bits which are multiple bits arechannel-coded (using the RM code, a TBCC, a punctured RM code, and thelike) to generate ACK/NACK coded bits, and may be a sequence ofmodulated symbols in which the ACK/NACK coded bits are modulated (forexample, QPSK-modulated). The sequence of the modulated symbols ismapped in data symbols of the slot through fast Fourier transform (FFT)and inverse fast Fourier transform (IFFT) and thereafter, transmitted.FIG. 8 exemplifies the case in which three RS symbols exist in one slot,but two RS symbols may exist and in this case, a block spreading codehaving a length of 5 may be used.

[Semi-Persistent Scheduling (SPS)]

The UE in the wireless communication system receives schedulinginformation such as the DL grant and the UL grant through the PDCCH, andthe UE performs an operation of receiving the PDSCH and the transmittingthe PUSCH based on the scheduling information. Generally, the DL grantand the PDSCH are received in the same subframe. In addition, in thecase of the FDD, the PUSCH is transmitted after four subframes from thesubframe receiving the UL grant. The LTE provides semi-persistentscheduling (SPS) in addition to the dynamic scheduling.

The downlink or uplink SPS may notify that semi-persistent transmission(PUSCH)/reception (PDSCH) from/to the UE is performed in any subframesthrough an higher layer signal such as radio resource control (RRC).Parameters provided to the higher layer signal may be, for example, aperiod and an offset value of the subframe.

When the UE receives activation and release signals of the SPStransmission through the PDCCH after recognizing the SPStransmission/reception through the RRC signaling, the SPStransmission/reception is performed or released. That is, even thoughthe UE receives the SPS through the RRC signaling, when the SPStransmission/reception is not directly performed and the activation orrelease signal is received through the PDCCH, the SPStransmission/reception is performed in the subframe corresponding to thesubframe period and the offset value received through the RRC signalingby applying a frequency resource (resource block) according to theresource block allocation assigned in the PDCCH, modulation according toMCS information, and the coding rate. When the release signal isreceived through the PDCCH, the SPS transmission/reception stops. Whenthe PDCCH (SPS reactivation PDCCH) including the activation signal isreceived again, the stopped SPS transmission/reception restarts by usingthe frequency resource assigned in the corresponding PDCCH, the MCS, andthe like.

Hereinafter, a PDCCH for SPS activation is referred to as an SPSactivation PDCCH, and a PDCCH for SPS release is referred to as an SPSrelease PDCCH. The UE may validate whether the PDCCH is the SPSactivation/release PDCCH in the case of satisfying the followingconditions. 1. CRS parity bits obtained from the PDCCH payload arescrambled to the SPS C-RNTI, and 2. A value of a new data indicatorfield needs to be ‘0’. Further, each field value included in the PDCCHis set as values of the following table, the UE receives the downlinkcontrol information (DCI) of the corresponding PDCCH as the SPSactivation or release.

TABLE 5 DCI format DCI format DCI format 0 1/1A 2/2A/2B TPC command forset to ‘00’ N/A N/A scheduled PUSCH Cyclic shift DM RS set to ‘000’ N/AN/A Modulation and coding MSB is N/A N/A scheme and redundancy set to‘0’ version HARQ process number N/A FDD: set FDD: set to ‘000’ to ‘000’TDD: set TDD: set to ‘0000’ to ‘0000’ Modulation and coding N/A MSB isFor the enabled scheme set to ‘0’ transport block: MSB is set to ‘0’Redundancy version N/A set to For the enabled ‘00’ transport block: setto ‘00’

Table 5 illustrates field values of the SPS activation PDCCH forvalidating the SPS activation.

TABLE 6 DCI format 0 DCI format 1A TPC command for scheduled set to ‘00’N/A PUSCH Cyclic shift DM RS set to ‘000’ N/A Modulation and codingscheme set to ‘11111’ N/A and redundancy version Resource blockassignment and Set to all ‘1’s N/A hopping resource allocation HARQprocess number N/A FDD: set to ‘000’ TDD: set to ‘0000’ Modulation andcoding scheme N/A set to ‘11111’ Redundancy version N/A set to ‘00’Resource block assignment N/A Set to all ‘1’s

Table 6 illustrates field values of the SPS release PDCCH for validatingthe SPS release.

By the SPS, a PDSCH transmitted in the same subframe as the PDCCHinstructing SPS activation has the corresponding PDCCH, but a subsequentPDSCH, that is, a PDSCH which is subsequently scheduled by the SPS (thisis assumed as an SPS PDSCH) has no corresponding PDCCH. Accordingly,when transmitting an ACK/NACK for the SPS PDSCH, it is impossible to usethe PUCCH resource mapped in the lowest CCE index of the PDCCH.Therefore, after predetermine a plurality of resources through an higherlayer signal such as an RRC message, the base station may indicate aACK/NACK transmission resource for the SPS PDSCH by a method ofindicating a specific resource among the plurality of resources byconverting a TPC field included in the PDCCH indicating the SPSactivation into an ACK/NACK resource indicator (ARI).

<HARQ(Hybrid Automatic Repeat Request)>

When the frame is not received or damaged upon the transmission andreception of the data between the base station and the user equipment,as an error control method, there are an automatic repeat request (ARQ)and a hybrid ARQ (HARQ) which is a more developed form. In the ARQmethod, an acknowledgement (ACK) message waits to go after transmittingone frame, a receiving side transmits the ACK message only whenreceiving one frame well, but transmits a negative-ACK(NACK) messagewhen an error occurs in the frame, and a receiving-side buffer deletesthe information of the received frame with the error. The transmittingside transmits a subsequent frame when receiving the ACK signal, butre-transmits the frame when receiving the NACK message.

Unlike the ARQ method, in the HARQ method, when the received frame maynot be demodulated, the receiving terminal transmits the NACK message tothe transmitting terminal, but a pre-received frame is stored in thebuffer for a predetermined time, and when the frame is re-transmitted,the frame is combined with the pre-received frame, thereby enhancing areception success rate.

Recently, the HARQ method which is more efficient than the ARQ methodhas been widely used. The HARQ method has various types, and largely,may be divided into a synchronous HARQ and an asynchronous HARQaccording to a retransmitting timing, and may be divided into achannel-adaptive method and a channel-non-adaptive method according towhether a channel state is reflected to an amount of the resources usedin the retransmission.

FIG. 9 exemplifies the synchronous HARQ.

The synchronous HARQ method is a method in which a subsequentretransmission is achieved at a timing defined by the system wheninitial transmission is failed. That is, when it is assumed that thetiming when the retransmission is performed is achieved every eighthtime unit (subframe) after the initial transmission, because this ispre-defined between the base station and the user equipment, the timingneeds not to be additionally notified. However, when the datatransmitting side receives the NACK message, the data transmitting sideretransmits the data every eighth time unit until receiving the ACKmessage.

On the other hand, the asynchronous HARQ method may be performed bynewly scheduling the retransmission timing or by additionally signaling.The timing of the retransmission for the data of which the transmissionis previously failed varies by various factors such as a channel stateand the like.

The channel-adaptive HARQ method is a method in which modulation of thedata upon the retransmission, the number of resource blocks, the codingschemes, and the like are made as provided in the initial transmission,and unlike this, the channel-non-adaptive HARQ method is a method inwhich the modulation of the data upon the retransmission, the number ofresource blocks, the coding schemes, and the like vary according to thechannel state.

For example, the channel-non-adaptive HARQ method is a method in whichthe transmitting side transmits the data by using six resource blocks inthe initial transmission and retransmits the data by using six resourceblocks equally even in the subsequent retransmission.

On the contrary, the channel-adaptive HARQ method is a method in whichthe transmitting side initially transmits the data by using six resourceblocks and thereafter, retransmits the data by using resource blockshaving the number which is larger or smaller than six according to thechannel state.

Four HARQ combinations may be performed by the classification, but asthe mainly used HARQ methods, there are the asynchronous andchannel-adaptive HARQ methods and the synchronous andchannel-non-adaptive HARQ methods. The asynchronous and channel-adaptiveHARQ methods may maximize the retransmission efficiency by adaptivelyvarying a retransmission timing and an amount of the used resourceaccording to the channel state, but are not generally considered for theuplink because there is a disadvantage that an overhead is increased.Meanwhile, the synchronous and channel-non-adaptive HARQ methods areadvantageous in that there is little overhead for the because the timingand the resource assignment for retransmission are committed in thesystem, but when the synchronous and channel-non-adaptive HARQ methodsare used in a channel state having a severe change, it isdisadvantageous that the retransmission efficiency is very low.

Currently, in 3GPP LTE, in the case of a downlink, the asynchronous HARQmethod has been used, and in the case of the uplink, the synchronousHARQ method has been used.

Meanwhile, as an example of the downlink, until the data is scheduledand transmitted and then the ACK/NACK signal is received from the userequipment and the next data is transmitted again, a time delay occurs asillustrated in FIG. 9. This is a propagation delay of the channel and adelay occurring due to a time required for data decoding and datacoding. For data transmission without a blank for the delay period, amethod of transmitting the data by using an independent HARQ process hasbeen used.

For example, when a shortest period from the next data transmission tothe next data transmission is eight subframes, the data may betransmitted without the blank by providing eight independent processes.In LTE FDD, in the case of not operating in the MIMO, a maximum of eightHARQ processes may be assigned.

[Carrier Aggregation]

Hereinafter, a carrier aggregation system will be described.

FIG. 10 illustrates a comparative example of a single carrier system inthe related art and a carrier aggregation system.

Referring to FIG. 10, in the single carrier system, only one carrier issupported to the UE in the uplink and the downlink. A bandwidth of thecarrier may be various, but the number of carriers allocated to the UEis one. On the contrary, in the carrier aggregation (CA) system, aplurality of component carriers DL CCs A to C and UL CCs A to C may beallocated to the UE. A component carrier (CC) means a carrier used inthe CA system and may be abbreviated as a carrier. For example, in orderto allocate a bandwidth of 60 MHz to the UE, three 20-MHz componentcarriers may be allocated.

The CA system may be divided into a contiguous CA system in whichaggregated carriers are contiguous and a non-contiguous CA system inwhich the aggregated carriers are separated from each other.Hereinafter, when simply referred to as the CA system, it should beunderstood that the CA system includes both the system in which thecomponent carriers are contiguous and the system in which the componentcarriers are not contiguous.

Component carriers to be targeted when one or more component carriersare aggregated may use a bandwidth used in the existing system forbackward compatibility with the existing system as it is. For example,in a 3GPP LTE system, bandwidths of 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15MHz, and 20 MHz are supported, and in a 3GPP LTE-A system, a wideband of20 MHz or more may be configured by using only the bandwidth of the 3GPPLTE system. Alternatively, the wideband may be configured by defining anew bandwidth without using the bandwidth of the existing system as itis.

A system frequency band of the wireless communication system is dividedinto a plurality of carrier-frequencies. Here, the carrier-frequencymeans a center frequency of a cell. Hereinafter, the cell may mean adownlink frequency resource and an uplink frequency resource. Further,the cell may mean a combination of the downlink frequency resource andan optional uplink frequency resource. Further, in general, when thecarrier aggregation (CA) is not considered, the uplink and downlinkfrequency resources may continuously exist as a pair in one cell.

In order to transmit and receive packet data through a specific cell,the UE should first complete a configuration for the specific cell.Herein, the configuration means a state in which the reception of thesystem information required to transmit and receive the data in thecorresponding cell is completed. For example, the configuration mayinclude a whole process of receiving common physical layer parametersrequired to transmit and receive the data, media access control (MAC)layer parameters, or parameters required for a specific operation in anRRC layer. The configured cell is in a state where transmission andreception of the packet are enabled immediately after only informationthat the packet data may be transmitted is received.

The configured cell may exist in an activation or deactivation state.Here, the activation means that the data is transmitted or received orin a ready state. The UE may monitor or receive a control channel PDCCHand a data channel PDSCH of the activated cell in order to verify aself-allocated resource (frequency, time, and the like).

The deactivation means that transmission or reception of the trafficdata is impossible, and measurement or transmission/reception of minimuminformation is possible. The UE may receive system information (SI)required to receive the packet from the deactivated cell. On the otherhand, the UE does not monitor or receive a control channel PDCCH and adata channel PDSCH of the deactivated cell in order to verify theself-allocated resource (frequency, time, and the like).

The cell may be divided into a primary cell, a secondary cell, and aserving cell.

The primary cell means a cell that operates at a primary frequency, andmeans a cell in which the UE performs an initial connectionestablishment procedure or a connection reestablishment procedure withthe base station, or a cell indicated as the primary cell during ahandover procedure.

The secondary cell means a cell that operates at a secondary frequency,and once RRC connection is established, the secondary cell is configuredand used to provide an additional radio resource.

The serving cell is configured as the primary cell in the case of an UEin which the CA is not configured or the CA cannot be provided. In thecase where the carrier aggregation is configured, the term of theserving cell represents a cell configured to the UE and a plurality ofserving cells may be constituted. One serving cell may be configured bya pair of one downlink component carrier or a pair of {downlinkcomponent carrier, uplink component carrier}. The plurality of servingcells may be configured by a set of the primary cell and one or aplurality of secondary cells.

A primary component carrier (PCC) means a component carrier (CC)corresponding to the primary cell. The PCC is a CC in which the UE isearly connected or RRC-connected with the BS, among many CCs. The PCC isa specific CC that performs connection or RRC-connection for signalingwith respect to a plurality of CCs and manages UE context informationwhich is connection information associated with the UE. Further, the PCCis connected with the UE and continuously exists in the activation statein the case of an RRC connected mode. A downlink component carriercorresponding to the primary cell is referred to as a downlink primarycomponent carrier (DL PCC), and an uplink component carriercorresponding to the primary cell is referred to as an uplink primarycomponent carrier (UL PCC).

A secondary component carrier (SCC) means a CC corresponding to thesecondary cell. That is, the SCC, as a CC allocated to the UE inaddition to the PCC, is an extended carrier for additional resourceallocation and the like of the UE in addition to the PCC, and may bedivided into activation and deactivation states. A downlink componentcarrier corresponding to the secondary cell is referred to as a DLsecondary CC (DL SCC), and an uplink component carrier corresponding tothe secondary cell is referred to as an UL secondary CC (UL SCC).

The primary cell and the secondary cell have the following features.

First, the primary cell is used for transmission of the PUCCH. Second,the primary cell is continuously activated, while the secondary cell isa carrier activated/deactivated according to a specific condition.Third, when the primary cell experiences a radio link failure(hereinafter referred to as an RLF), the RRC-reconnection is triggered.Fourth, the primary cell may be changed by a security key or a handoverprocedure accompanied with a random access channel (RACH) procedure.Fifth, non-access stratum (NAS) information is received through theprimary cell. Sixth, in the FDD system, the primary cell is alwaysconstituted by a pair of the DL PCC and the UL PCC. Seventh, a differentcomponent carrier (CC) for each UE may be configured as the primarycell. Eighth, the primary cell may be replaced only through handover,cell selection/cell reselection processes. In the addition of a newsecondary cell, RRC signaling to transmit system information of adedicated secondary cell may be used.

In the component carrier constituting the serving cell, the downlinkcomponent carrier may constitute one serving cell, and the downlinkcomponent carrier and the uplink component carrier areconnection-configured to constitute one serving cell. However, theserving cell is not constituted by only one uplink component carrier.

Activation/deactivation of the component carrier is equivalent to, thatis, a concept of activation/deactivation of the serving cell. Forexample, assumed that serving cell 1 is constituted by DL CC1,activation of serving cell 1 means activation of DL CC1. Assumed thatserving cell 2 is constituted by connection-configuring DL CC2 and ULCC2, activation of serving cell 2 means activation of DL CC2 and UL CC2.In the meantime, each component carrier may correspond to the servingcell.

The number of component carriers aggregated between the downlink and theuplink may be differently set. A case in which the number of downlinkCCs and the number of uplink CCs are the same as each other is referredto as symmetric aggregation, and a case in which the numbers aredifferent from each other is referred to as asymmetric aggregation.Further, sizes (that is, bandwidths) of the CCs may be different fromeach other. For example, when it is assumed that five CCs are used toconfigure a 70 MHz-band, the five CCs may be constituted by a 5 MHz CC(carrier #0), a 20 MHz CC (carrier #1), a 20 MHz CC (carrier #2), a 20MHz CC (carrier #3), and a 5 MHz CC (carrier #4).

As described above, the CA system may support a plurality of componentcarriers (CCs), that is, a plurality of serving cells, unlike the singlecarrier system.

The CA system may support cross-carrier scheduling. The cross-carrierscheduling may be a scheduling method that may perform resourceallocation of the PDSCH transmitted through other component carriersthrough the PDCCH transmitted through a specific component carrierand/or resource allocation of the PUSCH transmitted through othercomponent carriers in addition to the component carrier which isbasically linked with the specific component carrier. That is, the PDCCHand the PDSCH may be transmitted through different DL CCs, and the PUSCHmay be transmitted through another UL CC which is not the UL CC linkedwith the DL CC transmitted by the PDCCH including a UL grant. As such,in the system supporting the cross-carrier scheduling, a carrierindicator indicating that the PDCCH notifies that the PDSCH/PUSCHproviding control information is transmitted through any DL CC/UL CC. Afield including the carrier indicator may be hereinafter called acarrier indication field (CIF).

The CA system supporting the cross-carrier scheduling may include acarrier indication field (CIF) in an existing downlink controlinformation (DCI) format. In the system supporting the cross-carrierscheduling, for example, the LTE-A system, since the CIF is added to theexisting DCI format (that is, the DCI format used in the LTE), 3 bitsmay be extended, and the PDCCH structure may reuse an existing codingmethod, a resource allocating method (that is, resource mapping based onthe CCE), and the like.

The BS may configure a PDCCH monitoring DL CC (monitoring CC) set. ThePDCCH monitoring DL CC set is configured by some DL CCs among all theaggregated DL CCs, and when the cross-carrier scheduling is configured,the UE may perform PDCCH monitoring/decoding with respect to only the DLCC included in the PDCCH monitoring DL CC set. In other words, the BStransmits the PDCCH for the PDSCH/PUSCH to be scheduled through only theDL CC included in the PDCCH monitoring DL CC set. The PDCCH monitoringDL CC set may be set UE-specifically, UE group-specifically, orcell-specifically.

Hereinafter, in 3GPP LTE, ACK/NACK transmission for the HARQ will bedescribed.

In FDD, the user equipment for supporting aggregation for a maximum oftwo serving cells transmits the ACK/NACK by using the PUCCH format 1busing channel selection when two serving cells are configured.

The user equipment for supporting aggregation for two or more servingcells transmits the ACK/NACK by using the PUCCH format 1b or the PUCCHformat 3 using the channel selection according to a configuration of thehigher layer signal when two or more serving cells are configured. Thechannel selection will be described below.

A UL subframe and a DL subframe coexist in one radio frame in the TDD,unlike in frequency division duplex (FDD). In general, the number of ULsubframes is less than the number of DL subframes. Therefore, inpreparation for a case in which the UL subframes for transmitting anACK/NACK signal are insufficient, it is supported that a plurality ofACK/NACK signals for a plurality of DL transport blocks are transmittedin one UL subframe.

Two ACK/NACK modes, i.e., channel selection and bundling, are supportedaccording to a higher layer configuration for a UE which does notsupport an aggregation of 2 or more than 2 serving cells in TDD.

First, the bundling is an operation in which, if all of PDSCHs (i.e., DLtransport blocks) received by a UE are successfully decoded, ACK istransmitted, and otherwise NACK is transmitted. This is called an ANDoperation. However, the bundling is not limited to the AND operation,and may include various operations for compressing ACK/NACK bitscorresponding to a plurality of transport blocks (or codewords). Forexample, the bundling may indicate a counter value indicating the numberof ACKs (or NACKs) or the number of consecutive ACKs.

Second, the channel selection is also called ACK/NACK multiplexing. TheUE transmits the ACK/NACK by selecting one of a plurality of PUCCHresources.

Table 5 below shows a DL subframe n-k associated with a UL subframe ndepending on the UL-DL configuration in 3GPP LTE. Herein, kεK, where Mis the number of elements of a set K.

TABLE 7 UL-DL Config- Subframe n uration 0 1 2 3 4 5 6 7 8 9 0 — — 6 — 4— — 6 — 4 1 — — 7, 6 4 — — — 7, 6 4 — 2 — — 8, 7, 4, 6 — — — — 8, 7, — —4, 6 3 — — 7, 6, 11 6, 5 5, 4 — — — — — 4 — — 12, 8, 7, 11 6, 5, — — — —— — 4, 7 5 — — 13, 12, 9, 8, — — — — — — — 7, 5, 4, 11, 6 6 — — 7 7 5 —— 7 7 —

Assume that M DL subframes are associated with a UL subframe n, whereM=3. Since 3 PDCCHs can be received from 3 DL subframes, the UE canacquire 3 PUCCH resources n⁽¹⁾ _(PUCCH,0), n⁽¹⁾ _(PUCCH,2). An exampleof channel selection is shown in Table 6 below.

TABLE 6 HARQ-ACK(0), HARQ- ACK(1), HARQ-ACK(2) n⁽¹⁾ _(PUCCH) b(0), b(1)ACK, ACK, ACK n⁽¹⁾ _(PUCCH, 2) 1, 1 ACK, ACK, NACK/DTX n⁽¹⁾ _(PUCCH, 1)1, 1 ACK, NACK/DTX, ACK n⁽¹⁾ _(PUCCH, 0) 1, 1 ACK, NACK/DTX, NACK/DTXn⁽¹⁾ _(PUCCH, 0) 0, 1 NACK/DTX, ACK, ACK n⁽¹⁾ _(PUCCH, 2) 1, 0 NACK/DTX,ACK, NACK/DTX n⁽¹⁾ _(PUCCH, 1) 0, 0 NACK/DTX, NACK/DTX, ACK n⁽¹⁾_(PUCCH, 2) 0, 0 DTX, DTX, NACK n⁽¹⁾ _(PUCCH, 2) 0, 1 DTX, NACK,NACK/DTX n⁽¹⁾ _(PUCCH, 1) 1, 0 NACK, NACK/DTX, NACK/DTX n⁽¹⁾ _(PUCCH, 0)1, 0 DTX, DTX, DTX N/A N/A

HARQ-ACK(i) denotes ACK/NACK for an i^(th) DL subframe among the M DLsubframes. Discontinuous transmission (DTX) implies that a DL transportblock cannot be received on a PDSCH in a corresponding DL subframe or acorresponding PDCCH cannot be detected. In Table 6 above, there arethree PUCCH resources n⁽¹⁾ _(PUCCH,0), n⁽¹⁾ _(PUCCH,1), and n⁽¹⁾_(PUCCH,2), and b(0) and b(1) are 2 bits transmitted by using a selectedPUCCH.

For example, if the UE successfully receives three DL transport blocksin three DL subframes, the UE transmits bits (1,1) through the PUCCH byusing n⁽¹⁾ _(PUCCH,2). If the UE fails to decode the DL transport blockand successfully decodes the remaining transport blocks in a 1^(st)(i=0) DL subframe, the UE transmits bits (0, 1) through the PUCCH byusing n⁽¹⁾ _(PUCCH,2).

In channel selection, NACK and DTX are coupled if at least one ACKexists. This is because a combination of a reserved PUCCH resource and aQPSK symbol is not enough to express all ACK/NACK states. However, ifthe ACK does not exist, the DTX and the NACK are decoupled.

The existing PUCCH format 1b may transmit only the ACK/NACK of 2 bits.However, the PUCCH format 1b using the channel selection represents moreACK/NACK states by linking a combination of the assigned PUCCH resourcesand the modulation symbol (2 bits) with a state of a plurality ofACK/NACKs.

In TDD, when UL-DL configuration is 5 and the user equipment does notsupport aggregation of two or more serving cells, only bundling issupported.

In TDD, in the case of the user equipment supporting the aggregation oftwo or more serving cells, when two or more serving cells areconfigured, the user equipment transmits the ACK/NACK by using one ofthe PUCCH format 1b with channel selection or the PUCCH format 3according to the upper layer configuration.

In TDD, the user equipment supporting the aggregation of two or moreserving cells is configured by the higher layer signal so as to use thebundling and transmits the ACK/NACK by using one of the PUCCH format 1bwith channel selection or the PUCCH format 3 according to the upperlayer configuration even when one serving cell is configured.

Even in FDD, a table similar to Table 8 is defined and the ACK/NACK maybe transmitted according to the table.

Hereinafter, the present invention will be described.

In a future wireless communication system, machine type communication(MTC), carrier aggregation using different TDD UL-DL configurations, andthe like may be used. As a result, various types of services may beprovided and an increase in the number of user equipments simultaneouslyscheduled is expected. Accordingly, it is difficult to perform smoothscheduling on an exiting control channel scheduling the data channel.

In LTE, a control channel transmitting control information is a PDCCH.In order to solve a resource shortage phenomenon of the PDCCH, bundledscheduling for scheduling the PDSCH transmitted through a plurality ofsubframes or a plurality of CCs through one PDCCH, cross-subframescheduling for flexibility of PUCCH application, and the like have beenconsidered. Further, unlike the existing PDCCH, introduction of anenhanced-PDCCH (e-PDCCH) configuring the control channel in the PDSCHregion has been also considered.

Meanwhile, in order to transmit the ACK/NACK which is theacknowledgement for the data channel scheduled through the controlchannel, a transmit diversity may be used. The transmit diversity meansa technique of transmitting the same information through differentantenna ports. One type of transmit diversity includes a spatiallyorthogonal resource transmit diversity (SORTD). The SORTD is a transmitdiversity technique of simultaneously transmitting the same signal byusing spatially orthogonal resources.

In the case of LTE, the ACK/NACK for the PDSCH may be transmittedthrough the PUCCH format 1a/1b. In this case, the ACK/NACK istransmitted after a minimum of preparation time by consideringpropagation delay of the user equipment/base station receiving the data,a processing time required for processing of control information/datareception, and the like. The minimum of preparation time is representedby a subframe unit to become a k_(m) (for example, 4) subframe.

In FDD, the ACK/NACK for the data is transmitted after 4 subframes fromthe subframe receiving the data. In the case of TDD, an ACK/NACKtransmission time is defined by considering a ratio of the number of DLsubframes in the radio frame to the number of UL subframes so that theACK/NACK transmission is not concentrated in a specific UL subframe.

The following table represents a time relationship of transmitting theACK/NACKs for the plurality of DL subframes corresponding to one ULsubframe (Table 9 is the same as Table 7, but represented again forconvenience).

TABLE 9 UL-DL Config- Subframe n uration 0 1 2 3 4 5 6 7 8 9 0 — — 6 — 4— — 6 — 4 1 — — 7, 6 4 — — — 7, 6 4 — 2 — — 8, 7, 4, 6 — — — — 8, 7, — —4, 6 3 — — 7, 6, 11 6, 5 5, 4 — — — — — 4 — — 12, 8, 7, 11 6, 5, — — — —— — 4, 7 5 — — 13, 12, 9, 8, — — — — — — — 7, 5, 4, 11, 6 6 — — 7 7 5 —— 7 7 —

Table 9 represents that subframe 2 of UL-DL configuration 0 is the ULsubframe and the ACK/NACK for the data received in the DL subframebefore 6 subframes is transmitted in the subframe 2. In each UL suframe,a plurality of ACK/NACKs may be transmitted by using ACK/NACK bundlingand ACK/NACK multiplexing.

Meanwhile, the ACK/NACK includes an ACK/NACK for the PDSCH scheduled bythe PDCCH and an ACK/NACK for the PDCCH itself. The ACK/NACK for thePDCCH itself may be, for example, an ACK/NACK for a DL SPS releasePDCCH. A PDCCH resource used in the ACK/NACK transmission may beimplicitly determined as a resource corresponding to the PDCCH. That is,a resource linked with the lowest CCE index among the CCEs configuringthe PDCCH may be a PUCCH resource transmitting the ACK/NACK.

The implicit PUCCH resource described above is defined only bycorresponding to 1) the UL subframe after 4 subframes in the DL subframein FDD and a DL subframe-UL subframe of Table 9 in TDD.

Meanwhile, in the ACK/NACK, an ACK/NACK for the PDSCH scheduled withoutthe PDCCH may be included. For example, this case is the ACK/NACK forthe PDSCH by the SPS. In this case, since the PDCCH corresponding to thePDSCH does not exists, there is a problem in that the implicit PUCCHresource described above may not be determined.

Accordingly, the base station may notify the PUCCH resource for ACK/NACKtransmission by a method of assigning one of the plurality of resourcesthough the ARI after pre-assigning the plurality of resources throughthe higher layer signal such as the RRC message. The PUCCH resource bythe method is called an explicit PUCCH resource. The ARI may be includedin the PDCCH activating the SPS and borrow a transmission power control(TPC) field.

In LTE-A, in the case of transmitting the ACK/NACK through the PUCCHformat 1a/1b (alternatively, the PUCCH format 1a/1b with channelselection), the ACK/NACK for the PDSCH scheduled by the PDCCH positionedin a primary cell and the ACK/NACK for the PDCCH itself uses the PUCCHresource implicitly indicated from the PDCCH of the primary cell.

When the ACK/NACK for the PDSCH of a secondary cell scheduled by thePDCCH of the secondary cell to which non-cross carrier scheduling isapplied and the ACK/NACK for the PDSCH without the corresponding PDCCHadditionally exist, the ACK/NACK is transmitted by 1) selectively usingan implicit PUCCH resource linked with the CCE index occupied by thePDCCH of the primary cell and an explicit PUCCH resource indicated bythe ARI or 2) selectively using an explicit PUCCH resource for the PDSCHwithout the corresponding PDCCH and an explicit PUCCH resource for thesecondary cell.

Meanwhile, all the ACK/NACKs are transmitted only to the primary cell.In the case of defining the PUCCH resource of the primary cellcorresponding to the CCE occupied by the PDCCH of the secondary cell,collision with the PUCCH resource of the primary cell corresponding tothe CCE occupied by the PDCCH of the primary cell may occur. In order toavoid the problem and a problem of unnecessarily ensuring more implicitPUCCH resources, mapping of the CCE and the implicit PUCCH resource isnot defined between different carriers (cells). Further, in the case ofthe SPS, since there is no PDCCH, the implicit PUCCH resourcecorresponding to the CCE configuring the PDCCH may not be selected.

FIG. 11 illustrates an example of implicit PUCCH resource mapping insingle antenna port transmission.

Referring to FIG. 11A, one implicit PUCCH resource a0 corresponding to aCCE 111 having the lowest index n_(CCE) among CCEs configuring the PDCCHof a primary cell Pcell is determined.

A scheme of FIG. 11A may be applied when the implicit PUCCH resource isselected from the PDCCH of one cell in FDD or when the implicit PUCCHresource is selected from the PDCCH scheduling the PDSCH (of the primarycell or the secondary cell) of one codeword (CW) transmission mode in achannel selection scheme.

Referring to FIG. 11B, two implicit PUCCH resources a0 and a1corresponding to the CCE 112 having the lowest index n_(CCE) and a CCE113 having the second lower index n_(CCE+1) among the CCEs configuringthe PDCCH of the primary cell are determined.

In FIG. 11B, the channel selection scheme is applied and may be appliedwhen the implicit PUCCH resource is selected from the PDCCH schedulingthe PDSCH of the transmission mode of maximum 2 CWs.

Meanwhile, in the single antenna transmission using the PUCCH format1a/1b, as illustrated in FIG. 11A, when one implicit PUCCH resource ismapped from one PDCCH, the PUCCH transmit diversity may be applied. Asthe transmit diversity scheme, the SORTD may be applied, and in thiscase, the same signal is transmitted by using orthogonal resources intwo antenna ports. In this case, an antenna port in the single antennatransmission is referred to as a first antenna port and the otherantenna port added by applying the SORTD is referred to as a secondantenna port.

FIG. 12 illustrates an example of a method of determining the PUCCHresource used in two antenna ports, when the SORTD is applied as thePUCCH transmit diversity scheme.

Referring to FIG. 12, the PUCCH resource a0 corresponding to the lowestindex among indexes of the CCEs occupied by the PDCCH of the primarycell scheduling the PDSCH is used for the first antenna port and animplicit PUCCH resource a0′ corresponding to the second lower indexamong the indexes of the CCEs occupied by the PDCCH may be used for thesecond antenna port.

FIG. 13 illustrates another example of a method of determining the PUCCHresource used in two antenna ports, when the SORTD is applied as thePUCCH transmit diversity scheme.

FIG. 13 may be an example representing the method of determining thePUCCH resource used in the PUCCH transmit diversity, when two implicitPUCCH resources are mapped from one PDCCH in the single antennatransmission using the PUCCH format 1a/1b as illustrated in FIG. 11B.

Referring to FIG. 13, the implicit PUCCH resource a0 corresponding tothe lowest index n_(CCE) and the implicit PUCCH resource a1corresponding to the second lower index n_(CCE)+1 among the indexes ofthe CCEs occupied by the PDCCH of the primary cell scheduling the PDSCHmay be used for the first antenna port. In addition, the PUCCH resourcefor the second antenna port may use PUCCH resources a0′ and a1′corresponding to CCE indexes n_(CCE)+2 and n_(CCE)+3, respectively.

The following table represents an example of a RRC message (PUCCH-Configinformation element) for assignment for the PUCCH resource used inLTE-A.

TABLE 10 -- ASN1START PUCCH-ConfigCommon ::= SEQUENCE {  deltaPUCCH-Shift   ENUMERATED {ds1, ds2, ds3},   nRB-CQI   INTEGER(0..98),   nCS-AN   INTEGER (0..7),   n1PUCCH-AN   INTEGER (0..2047) }PUCCH-ConfigDedicated ::= SEQUENCE {   ackNackRepetition   CHOICE{    release     NULL,     setup     SEQUENCE {       repetitionFactor      ENUMERATED {n2, n4, n6, spare1},       n1PUCCH-AN-Rep      INTEGER (0..2047)     }   },   tdd-AckNackFeedbackMode ENUMERATED{bundling, multiplexing} OPTIONAL --   Cond TDD }PUCCH-ConfigDedicated-v1020 ::= SEQUENCE {   pucch-Format-r10   CHOICE {    format3-r10       SEQUENCE {       n3PUCCH-AN-List-r10 SEQUENCE(SIZE (1..4)) OF INTEGER (0..549) OPTIONAL,   -- Need ON      twoAntennaPortActivatedPUCCH-Format3-r10    CHOICE {        release NULL,         setup SEQUENCE {         n3PUCCH-AN-ListP1-r10  SEQUENCE (SIZE (1..4)) OF INTEGER(0..549)         }       } OPTIONAL -- Need ON     },    channelSelection-r10     SEQUENCE {       n1PUCCH-AN-CS-r10      CHOICE {         release         NULL,         setup        SEQUENCE {          n1PUCCH-AN-CS-List-r10       SEQUENCE (SIZE(1..2)) OF N1PUCCH-AN- CS-r10         }       } OPTIONAL  -- Need ON    }   } OPTIONAL, -- Need OR  twoAntennaPortActivatedPUCCH-Format1a1b-r10   ENUMERATED {true}OPTIONAL,   -- Need OR   simultaneousPUCCH-PUSCH-r10     ENUMERATED{true}   OPTIONAL,   -- Need OR   n1PUCCH-AN-RepP1-r10     INTEGER(0..2047)   OPTIONAL  -- Need OR } N1PUCCH-AN-CS-r10 ::= SEQUENCE (SIZE(1..4)) OF INTEGER (0..2047) -- ASN1STOP

According to Table 10, when the channel selection is used, since thetransmit diversity is not applied, only the resource assignment for thefirst antenna port is provided. In addition, when non-cross carrierscheduling is applied, the implicit resource assignment is required, andthe implicit resource assignment ‘N1PUCCH-AN-CS-r10’ is included in theRRC message. According to the number (one or two) of required PUCCHresources, a maximum of four indexes are provided by the RRC message,and the resource indicated by the ARI included in the PDCCH is used inthe ACK/NACK transmission.

<PUCCH Resource for SORTD of ACK/NACK for PDSCH without PDCCHCorresponding to Primary Cell>

When the ACK/NACK transmission for the PDSCH (for example, the SPSPDSCH) without the corresponding PDCCH is required, the single antennaport transmission using the PUCCH format 1a/1b may be performed. In thiscase, the PUCCH resource indicated by the ARI received from the PDCCHindicating the SPS activation among a maximum of four explicit PUCCHresources pre-configured by the RRC is used in the ACK/NACKtransmission.

When the SORTD is applied, the following RRC message may be provided.

TABLE 11 -- ASN1START SPS-Config ::= SEQUENCE {   semiPersistSchedC-RNTIC-RNTI OPTIONAL,   -- Need OR   sps-ConfigDL SPS-ConfigDL OPTIONAL,   --Need ON   sps-ConfigUL SPS-ConfigUL OPTIONAL   -- Need ON } SPS-ConfigDL::=  CHOICE{   release NULL,   setup SEQUENCE {    semiPersistSchedIntervalDL     ENUMERATED {       sf10, sf20, sf32,sf40, sf64, sf80,       sf128, sf160, sf320, sf640, spare6,      spare5, spare4, spare3, spare2,       spare1},    numberOfConfSPS-Processes     INTEGER (1..8),    n1PUCCH-AN-PersistentList     N1PUCCH-AN-PersistentList,     ...,    [[  twoAntennaPortActivated-r10      CHOICE {         release      NULL,         setup       SEQUENCE {          n1PUCCH-AN-PersistentListP1-r10 N1PUCCH-AN-PersistentList        }       } OPTIONAL  -- Need ON     ]]   } } SPS-ConfigUL ::=CHOICE {   release NULL,   setup SEQUENCE {    semiPersistSchedIntervalUL     ENUMERATED {       sf10, sf20, sf32,sf40, sf64, sf80,       sf128, sf160, sf320, sf640, spare6,      spare5, spare4, spare3, spare2,       spare1},    implicitReleaseAfter     ENUMERATED {e2, e3, e4, e8},    p0-Persistent     SEQUENCE {       p0-NominalPUSCH-Persistent      INTEGER (−126..24),       p0-UE-PUSCH-Persistent       INTEGER(−8..7)     }    OPTIONAL,                   -- Need OP    twoIntervalsConfig     ENUMERATED {true} OPTIONAL, -- Cond TDD    ...   } } N1PUCCH-AN-PersistentList ::= SEQUENCE (SIZE (1..4)) OFINTEGER (0..2047) -- ASN1STOP

According to Table 11, for the resource assignment for the first antennaport, a maximum of four indexes are provided, and the resource indicatedby the ARI included in the PDCCH indicating the SPS activation is used.Even in the second antenna port, similarly, a maximum of four indexesare provided, and the indexes are provided by independent indexes fromthe first antenna. In addition, the resource indicated by the ARIincluded in the PUCCH indicating the SPS activation is used.

Meanwhile, when resources required according to the ACK/NACKtransmission scheme are two, in the FDD, the explicit PUCCH resource a0indicated by the ARI and the PUCCH resource corresponding to a1=a0+1 maybe used. In the case of TDD, a pair of explicit PUCCH resources (a0, a1)indicated by the ARI may be used.

In addition to the aforementioned scheme, the SORTD may be applied inthe channel selection. In this case, in the SPS PDSCH transmission,whether two additional PUCCH resources for the second antenna port bythe SORTD are determined in any way will be described.

First, methods of determining two additional PUCCH resources for thesecond antenna port for the ACK/NACK transmission for the SPS PDSCH willbe described, in the case of using a0 and a1=a0+1 which are theresources defined by the ARI among the plurality of resources configuredby the RRC for the ACK/NACK transmission for the PDSCH (hereinafter,abbreviated as the SPS PDSCH for convenience) without the PDCCHcorresponding to the single antenna port transmission, 2) transmittingthe SORTD to the channel selection, and 3) transmitting the ACK/NACK forthe SPS PDSCH by the SORTD scheme. Hereinafter, a0 and a1 representresources used in the first antenna port (that is, the antenna port usedin the single antenna port transmission) for the ACK/NACK transmissionfor the SPS PDSCH, and a0′ and a1′ represent the resources used in thesecond antenna port for the ACK/NACK transmission for the SPS PDSCH.

First Embodiment

{a0, a1=a0+1, a0′=a2, a1′=a2+1} may be used by using a0 and a2 assignedas the first resource for each antenna port in addition to the a0. a2may be one resource pre-assigned to the user equipment by the RRC or oneof the plurality of resources. The ARI included in the SPS activatedPDCCH may indicate one resource.

The resource assigned for a2 may be selected among the plurality ofresources assigned for a0. For example, when {A,B,C,D} is assigned fora0 and one thereof is selected by the ARI, a2 may be a resource spacedapart from the resource selected by a0 among {A,B,C,D} at apredetermined interval. For example, in the case of a0=C, a2=A.

In the case of using the scheme, the PUCCH resource corresponding to thefirst antenna port may be equally maintained in 1) the case oftransmitting the ACK/NACK for the SPS PDSCH and 2) the case of applyingthe SORTD in the channel selection. Further, the number of PUCCHresources assigned to the RRC may be reduced.

Second Embodiment

(a2, a3) additionally assigned in addition to a0 may be used as a0′ anda1′ which are the PUCCH resources for the second antenna port.Accordingly, (a2, a3) may be {a0, a1=a0+1, a0′=a2, a1′=a3}.

(a2, a3) may be one resource pre-assigned to the user equipment or oneof the plurality of resource sets. One may be indicated by the ARIincluded in the PDCCH indicating the SPS activation.

The resource assigned for (a2, a3) may be selected among the pluralityof resources assigned for a0. For example, when {A,B,C,D} is assignedfor a0 and one thereof is selected by the ARI, (a2, a3) may be aresource spaced apart from the resource selected by a0 among {A,B,C,D}at a predetermined interval. For example, in the case of a0=C, (a2,a3)=(A, B). According to this scheme, the PUCCH resource correspondingto the first antenna port may be equally maintained. Further, theresource application may be flexible.

Third Embodiment

The PUCCH resources used when the ACK/NACK for the SPS PDSCH istransmitted to the SORTD may be {a0, a1=a0+1, a0′=a1+2, a1′=a1+3}. Themethod may be decreased in flexibility of the resource application, buthas an advantage of reducing an RRC signaling overhead.

Fourth Embodiment

{a0, a1, a0′, a1′} which are the PUCCH resources used when the ACK/NACKfor the SPS PDSCH is transmitted to the SORTD may be mapped in fourresources {A, B, C, D} indicated in plural for the ACK/NACK transmissionfor the SPS PDSCH. The {a0, a1, a0′, a1′} and the {A,B,C,D} may besequentially mapped regardless of the ARI or the {A,B,C,D} may be mappedin a cyclic-shifted form by the ARI. The method may be decreased inflexibility of the resource application, but has an advantage ofreducing an RRC signaling overhead.

Fifth Embodiment

The fifth embodiment is a method of configuring equally a resource to beapplied to the second antenna port in the case of transmitting theACK/NACK for the SPS PDSCH to the SORRD with a resource to be applied tothe second antenna port in the case of applying the SORTD to the channelselection.

In the case of applying the SORTD to the channel selection, the PUCCHresources to be assigned to the first antenna port may be implicitresources. In addition, the PUCCH resources to be assigned to the secondantenna port may be resources explicitly assigned by the RRC messageregardless of the implicit resources. The explicit resource for thesecond antenna port may be provided one by one per one PUCCH resourceused in the channel selection in the first antenna port. Alternatively,a plurality of explicit resources for the second antenna port isprovided through the RRC message and may be indicated one by one per oneof the PUCCH resources assigned to the first antenna port by the ARIincluded in the PDCCH.

In this case, the resources used in the second antenna port fortransmitting the ACK/NACK for the SPS PDSCH to the SORRD may beconfigured equally with the PUCCH resources assigned to the secondantenna port by the RRC message in the case of applying the SORTD to thechannel selection.

In this case, the assignment by the ‘N1PUCCH-AN-PersistentListP1-r10’included in the RRC message may be released or ignored.

In the embodiment, since the PUCCH resource of the second antenna portis equally used in the case of the SPS or not, in the case of schedulingthe PDSCH to the PDCCH again in the subframe where the SPS PDSCH isscheduled and overriding, ambiguity may occur. However, the ambiguitymay be classified by resource detected from the first antenna port.

FIG. 14 illustrates a method of transmitting the ACK/NACK by using theSORTD according to the fifth embodiment.

Referring to FIG. 14, the user equipment configures the PUCCH resourcefor the first antenna port (S110). The PUCCH resource for the firstantenna port may be an implicit PUCCH resource. When the channelselection is used, a plurality of implicit PUCCH resources may beprovided.

Alternatively, in the case of transmitting the ACK/NACK for the SPSPDSCH, the PUCCH resource for the first antenna port may be an implicitPUCCH resource indicated by the ARI among the plurality of resourcesconfigured by the RRC.

The user equipment configures the PUCCH resource for the second antennaport (S120). The PUCCH resource for the second antenna port may beprovided through the RRC message regardless of the implicit PUCCHresource for the first antenna port in the case of the channelselection. At this time, the PUCCH resource provided through the RRCmessage may be assigned one by one per one implicit PUCCH resource.

In this case, the PUCCH resource for the second antenna port for theSORTD transmission of the ACK/NACK for the SPS PDSCH may be provided bythe RRC message equally to the PUCCH resource for the second antennaport in the channel selection.

The user equipment transmits the same signal (that is, ACK/NACKresponse) by using the first and second antenna ports.

Next, methods of determining two additional PUCCH resources for thesecond antenna port for the ACK/NACK transmission for the SPS PDSCH willbe described, in the case of using (a0, a1) which is a pair of resourcesdefined by the ARI among a plurality of resource pairs configured by theRRC for the ACK/NACK transmission for the PDSCH (hereinafter,abbreviated as the SPS PDSCH for convenience) without the PDCCHcorresponding to the single antenna port transmission, 2) transmittingthe SORTD to the channel selection, and 3) transmitting the ACK/NACK forthe SPS PDSCH by the SORTD scheme.

(a2, a3) additionally assigned in addition to a0 and a1 may be used asa0′ and a1′ which are the PUCCH resources for the second antenna port.Accordingly, {a0, a1, a2, a3} is used. Herein, (a2, a3) is one of theplurality of sets pre-assigned to the user equipment, and one may beindicate by the ARI included in the PDCCH indicating the SPS activation.

Alternatively, as another method, a0, a1, a0′=a0+1, and a1′=a1+1 may beused. The method may be decreased in flexibility of the resourceapplication, but has an advantage of reducing an RRC signaling overhead.

Alternatively, as another method, a0, a1, a0′, and a1′ are used, a0′ mayuse an element next to a0 in the RRC set for a0 and a1′ may use anelement next to a1 in the RRC set for a1. This method may also bedecreased in flexibility of the resource application, but has anadvantage of reducing an RRC signaling overhead.

Alternatively, the same method as the aforementioned fifth embodimentmay be used. That is, in the case of applying the SORTD to the channelselection, the PUCCH resources to be assigned to the first antenna portmay be implicit resources. In addition, the PUCCH resources to beassigned to the second antenna port may be resources explicitly assignedby the RRC message regardless of the implicit resources. The explicitresource for the second antenna port may be provided one by one per onePUCCH resource used in the channel selection in the first antenna port.Alternatively, a plurality of explicit resources for the second antennaport is provided through the RRC message and may be indicated one by oneper one of the PUCCH resources assigned to the first antenna port by theARI included in the PDCCH.

In this case, the resources used in the second antenna port fortransmitting the ACK/NACK for the SPS PDSCH to the SORRD may beconfigured equally with the PUCCH resources assigned to the secondantenna port by the RRC message in the case of applying the SORTD to thechannel selection.

In the aforementioned embodiments, the ARI value included in the PDCCHindicating the SPS activation is used only in the PUCCH resourceconfiguration for the first antenna port and may be assumed as 0 whenselecting the PUCCH resource for the second antenna port. Alternatively,the ARI value is fixed to 0 to be applied to all the two antenna ports.

Meanwhile, in the technique, for convenience of the description, thePDCCH is exemplified, but even in the case of the e-PDCCH, the presentinvention may be equally applied.

<SORTD Resource Assignment in the Case where Simultaneous Transmissionof Multiple Cell ACK/NACK and CSI and Multiple CSI Transmission arePerformed by PUCCH Format 3>

In the case where the PUCCH format 3 is configured, the ACK/NACK for themultiple cells may occur. In this case, for the resource assignment forthe first antenna port, a maximum of four resources (of an index form)are provided, and the resource indicated by the ARI included in thePDCCH is used.

When the transmit diversity is applied, four resources (indexes) areprovided even in the second antenna port, and the resource indicated bythe ARI included in the PDCCH is used. Four indexes for the secondantenna port may be independent from four indexes for the first antennaport.

In LTE-A, performing the simultaneous transmission of the multiple cellACK/NACK and the CSI and the multiple CSI transmission through the PUCCHformat 3 has been considered. The multiple CSIs mean multiplexing andtransmitting a plurality of PUCCH reporting types and may include asingle cell ACK/NACK. The single cell ACK/NACK may be shown as the caseof the ACK/NACK configuration method when a condition where the TPCfield of the scheduled PDCCH is not borrowed by the ARI occurs. Thefollowing method may be applied in the PUCCH resource assignment for thetransmit diversity of the PUCCH format 3.

CASE 0: As the resource for the first antenna port, the simultaneoustransmission of the multiple cell ACK/NACK and the CSI and the multipleCSI transmission may be performed by using one resource configured bythe RRC. In this case, the resource for the second antenna port assignsone RRC resource and uses the allocated RRC resource. When the pluralityof RRC resources is configured, a specific RRC resource among the RRCresources may be used, and the specific RRC resource may be a firstresource configured by the RRC and may be a resource corresponding toARI=0.

CASE 1: As a resource for the first antenna port, the simultaneoustransmission of the multiple cell ACK/NACK and the CSI uses the resourceindicated by the ARI among the plurality of resources configured by theRRC, the multiple CSIs may be transmitted by using one resourceconfigured by the RRC. In this case, the resource for the second antennaport commonly assigns one resource configured by the RRC in thesimultaneous transmission of the multiple cell ACK/NACK and the CSI andthe multiple CSI transmission and uses the same resource.

When a plurality of RRC resources is configured, a specific RRC resourceamong the RRC resources may be predetermined to be used. For example,the specific RRC resource may be a first resource configured by the RRCand may be a resource corresponding to ARI=0. In the case of the secondantenna port, ambiguity for any case of both the simultaneoustransmission of the multiple cell ACK/NACK and the CSI and thetransmission of the multiple CSIs by using the same resource may occur.The ambiguity may be solved by detecting the resource used in the firstantenna port.

Alternatively, as a resource for the second antenna port, in the case ofthe simultaneous transmission of the multiple cell ACK/NACK and the CSI,the resource indicated by the ARI among the plurality of resourcesconfigured by the RRC may be used, and in the case of the transmissionof the multiple CSIs, one resource configured by the RRC may be assignedand used.

Alternatively, as a resource for the second antenna port, in the case ofthe simultaneous transmission of the multiple cell ACK/NACK and the CSI,the resource indicated by the ARI among the plurality of resourcesconfigured by the RRC may be used, and in the case of the transmissionof the multiple CSI, only the first antenna port may be transmittedwithout applying the transmit diversity. In the case of the transmissionof the multiple CSI, since error requirements are relatively small, aproblem of the performance deterioration even in the single antenna porttransmission may not be large.

In the CASED and the CASE 1, in the transmission of the multiple CSI andthe simultaneous transmission of the multiple cell ACK/NACK and the CSI,whether the transmit diversity is independently applied may beconfigured.

<Implicit PUCCH Resource for SORTD in the Case where e-PDCCH is Used>

FIG. 15 illustrates an example of e-PDCCH assignment.

In LTE-A, assigning and using the e-PDCCH which is a new control channelin the data area has been considered. The e-PDCCH configures anenhanced-CCE (e-CCE) like the PDCCH and may apply implicit PUCCHresource mapping based on the configured e-CCE. When the ARI is includein the e-PDCCH, an offset using the ARI may be used.

FIG. 16 illustrates an example of a method of configuring the offset bythe ARI.

Referring to FIG. 16, the mapping of the e-PDCCH and the implicit PUCCHresource in the single antenna transmission may assign the implicitresource by using the e-CCE index configuring the e-PDCCH and the PUCCHindex corresponding to the offset value by the ARI.

In detail, FIG. 16A illustrates an example of the mapping of oneimplicit PUCCH resource corresponding to the e-CCE and FIG. 16Billustrates an example of the mapping of two implicit PUCCH resourcescorresponding to the e-CCE.

As illustrated in FIG. 16A, the PUCCH resource a0 corresponding to a sum(that is, the first index n_(e-CCE) of the e-CCE+Offset_(ARI)) of thelowest index among the indexes of the e-CCEs configuring the e-PDCCH andthe offset value by the ARI may be used in the ACK/NACK transmission.

Alternatively, as illustrated in FIG. 16B, two PUCCH resources a0 and a1corresponding to η_(e-CCE)+Offset_(ARI) and n_(e-CCE)+1+Offset_(ARI) maybe used in the ACK/NACK transmission.

In FIG. 16A, when the implicit PUCCH resource is selected from thee-PDCCH of the single cell in FDD, a case of selecting the implicitPUCCH resource in the e-PDCCH scheduling the PDSCH which is a 1 CWtransmission mode in the channel selection may be applied.

In the channel selection, FIG. 16B may be applied when the implicitPUCCH resource is selected from the e-PDCCH scheduling the PDSCH in thetransmission mode of a maximum of 2 CWs.

In the single antenna port transmission using the PUCCH format 1a/1b, asillustrated in FIG. 16A, it is assumed a case where one implicit PUCCHresource is mapped from one e-PDCCH. In this case, a PUCCH transmitdiversity is applied and the technique thereof may be the SORTD. In thiscase, whether the resource for the second antenna port is determined inany way may be a problem.

FIG. 17 illustrates an example of determining the resource for thesecond antenna port.

Referring to FIG. 17, the PUCCH resource a0 corresponding to the sum ofthe minimum index occupied by the e-PDCCH scheduling the PDSCH and theoffset value by the ARI is used as the resource for the first antennaport, and the PUCCH resource a0′ corresponding to the sum of the minimumindex+1 occupied by the e-PDCCH scheduling the PDSCH and the offsetvalue by the ARI may be used as the resource for the second antenna portfor the SORTD. When a range of the PUCCH resource corresponding ton_(e-CCE) is defined, the mapping may be performed through a modularoperation within the corresponding range.

In the single antenna port transmission using the PUCCH format 1a/1b, asillustrated in FIG. 16B, it is assumed a case where two implicit PUCCHresources are mapped from one e-PDCCH. In this case, whether theresource for the second antenna port is determined in any way may be aproblem.

FIG. 18 illustrates an example of resource mapping for the secondantenna port in the case where the PUCCH transmit diversity is appliedand the SORTD is applied as the technique thereof.

Referring to FIG. 18, the resource for the first antenna port may be thePUCCH resource a0 corresponding to the sum (n_(e-CCE)+Offset_(ARI)) ofthe minimum index occupied by the e-PDCCH scheduling the PDSCH and theoffset value by the ARI and the PUCCH resource a1 corresponding ton_(e-cu)+1+Offset_(ARI). In this case, the resource for the secondantenna port may be PUCCH resources a0′ and a1′ corresponding ton_(e-CCE)+2+Offset_(ARI) and n_(e-CCE)+3+Offset_(ARI).

<Method of Configuring Resource for Second Antenna Port for SORTD ofe-PDCCH and Two Resources for Channel Selection>

A case where the PUCCH format 1/1a/1b is used is assumed. In the case ofusing the e-PDCCH, in the scheduling of the primary cell, similarly tothe PDCCH, the implicit PUCCH resource corresponding to the e-CCEoccupied by the e-PDCCH may be used. That is, a correspondence betweenthe e-CCE and the PUCCH resource index is predetermined and the resourcea0 corresponding to the e-CCE is used as the PUCCH resource for thefirst antenna port.

When the SORTD is configured, the PUCCH resource for the second antennaport is required.

The PUCCH resource a0′ for the second antenna port may be determined asfollows.

1) a0′=a0+1 may be used.

2) One explicit resource may be assigned. That is, a0′=RRC configuredvalue may be used.

When the PUCCH format 1b using the channel selection is used in thesingle antenna port transmission, in the case of using the e-PDCCH, likethe PDCCH scheduled in the primary cell, the implicit PUCCH resource(referred to as ax) corresponding to the e-CCE occupied by the e-PDCCHmay be used. When the cell configured in the 2 CW transmission mode isincluded, securing of two PUCCH resources from the corresponding cellmay be required. In this case, when the second resource is ay, ay=ax+1or ay′ (the PUCCH resource used in the second antenna port) may bedetermined based on the RRC configuration value.

<Configuration of Resource for Second Antenna Port for SORTD when PUCCHand e-PDCCH Coexist>

As described above, in the case of the PUCCH, the implicit PUCCHresource corresponding to the CCE occupied by the PDCCH is used in theACK/NACK transmission. Like the e-PDCCH, the implicit PUCCH resourcecorresponding to the e-CCE occupied by the e-PDCCH may be used in theACK/NACK transmission. As such, when the implicit resource correspondingto the CCE or the e-CCE is configured, different user equipments areconfigured so as not to be duplicated if necessary because of sharingthe common resource.

Meanwhile, in the case of applying the SORTD in the PUCCH format 1b withthe channel selection, the resource for the second antenna port may beexplicitly assigned through the RRC by the number of PUCCH resourcesrequired in the channel selection of the first antenna port. In thiscase, one resource for the second antenna port per one resource for thefirst antenna port may be assigned. This is to avoid limit requirementsof possibility of acquiring the ARI and simply assign the resources.

In one user equipment, when schedulings by the PDCCH and the e-PDCCHcoexist, the resources for the second antenna port using the explicitresource may be commonly shared and used.

In the case of scheduling the PDSCH of a specific cell to the userequipment, the implicit PUCCH resource needs to be scheduled so that theresource collision between different user equipments does not occur, butsince the explicit resource is exclusively used to the correspondinguser equipment, the collision problem does not occur. Further, since theuser equipment receives the PDSCH scheduling of the corresponding cellby only one of both the PDCCH and the e-PDCCH, whether the PDSCH isscheduled by the PDCCH and whether the PDSCH is scheduled by the e-PDCCHneed not to be separately divided.

When the user equipment receives the PDSCH scheduling by the PDCCH andreceives the PDSCH by the SPS and when the user equipment receives thePDSCH scheduling by the e-PDCCH and receives the PDSCH by the SPS, theuser equipment may receive the same explicit PUCCH resource.

Further, in the case of receiving the PDSCH by the non-cross carrierscheduling through the secondary cell (that is, receiving thePDCCH-PDSCH through the secondary cell), the ACK/NACK for the PDSCH istransmitted through the explicit PUCCH resource. In this case, theexplicit PUCCH resource may be equally configured regardless of whetherthe user equipment uses the scheduling by the PDCCH or the scheduling bythe e-PDCCH. That is, the ACK/NACK for the PDSCH of the secondary cellby self-scheduling may be transmitted by using the same explicit PUCCHresource regardless of whether any one of the PDCCH/e-PDCCH is used inthe control channel of the primary cell.

Further, even in the case where the user equipment receiving the PUCCHformat 1b using the channel selection transmits the ACK/NACK by theSORTD, the resource of the first antenna port may vary according to ause of the PDDCH or the e-PDCCH as the implicit resource, but in thecase of the PUCCH resource corresponding to the second antenna port, thesame explicit PUCCH resource may be used regardless of a kind of controlchannel of the primary cell.

The present invention may be similarly applied even in the case of usingdifferent implicit resources, as the resources for the first antennaport determined by a localized e-PDCCH and a distributed e-PDCCH. Bothin the case of being scheduled by the localized e-PDCCH and the case ofbeing scheduled by the distributed e-PDCCH, the explicit resources forthe second antenna port may be commonly shared and used.

<Single Antenna Port Transmission and PUCCH Resource for SORTD in theCase where there is No Implicit Resource Corresponding to PDCCH ore-PDCCH Positioned in Primary Cell>

FIG. 19 illustrates an example of subframe bundled scheduling.

Referring to FIG. 19, one PDCCH schedules the PDSCHs transmitted in aplurality of subframes. In this case, the number B of subframessimultaneously scheduled is configured by the RRC or included in thePDCCH to be notified to the user equipment.

In FDD, the PDSCHs by the subframe bundled scheduling are assigned byone HARQ process, and one TB is transmitted through the PDSCHs of theplurality of subframes and only one ACK/NACK for one TB is required.However, when spatial multiplexing is applied, TBs which are as many asthe number of multiplexed codewords are transmitted through theplurality of PDSCHs, and in this case, the number of ACK/NACKs isincreased by the number of TBs. In the case of operating as a singlecell configured in a transmission mode of a maximum of 2 codewords, theuser equipment may transmit the ACK/NACK by using the PUCCH format1a/1b.

In the case of B=1 as the PUCCH resource for the PUCCH format 1a/1b, theimplicit PUCCH resource may be used. On the contrary, in the case ofB>l, implicit resources between DL-UL are not defined. Accordingly, theexplicit PUCCH resource indicated by the ARI among the plurality ofresources reserved by the RRC is used. When the SORTD is used, a pair ofexplicit resources indicated by the ARI among the plurality of pairs ofexplicit resources reserved by the RRC is used.

Similarly, even in TDD, if mapping of the DL subframe in which the PDCCHis transmitted and the implicit PUCCH resource exists, the implicitPUCCH resource is used, and if not, the explicit PUCCH resource is used.

However, in the case of TDD, since a plurality of bundling windows maycorrespond to one UL subframe, the PUCCH format 2 or the PUCCH format 1bwith the channel selection may be used. When the SORTD is applied, inthe method of assigning the PUCCH resource, other resources may beconfigured and used according to whether the PUCCH resource is animplicit resource or an explicit resource in the single antenna porttransmission.

Meanwhile, the subframe bundled scheduling may be assigned only withrespect to a specific subframe configured by considering an inter-cellinterference coordination (ICIC). For example, the subframe bundledscheduling may be applied only to a set except for an almost blanksubframe (ABS).

Information on the subframe to which the subframe bundled scheduling isapplied may be broadcasted or signaled by the RRC. Alternatively, theinformation may be received with respect to a subframe to which thesubframe (that is, the subframe transmitted with the PDCCH) includingthe control information by the subframe bundled scheduling belongs. Thesubframe set may be divided into an e-PDCCH/PDCCH monitoring subframeset, a CSI subframe set, and a CSI process-target subframe set. Theinformation may indicate the number of consecutive subframes from thesubframe in which the PDCCH is transmitted and whether to schedule thePDSCH of each subframe in a bitmap form corresponding to each of Bsubframes.

FIG. 20 illustrates an example of cross subframe scheduling.

The cross subframe scheduling means scheduling PDSCHs through theplurality of subframes by each of the plurality of PDCCHs included inthe PDCCH area of one subframe.

FIG. 20A is an example of the FDD, and a method of transmitting eachACK/NACK in the UL subframe corresponding to the DL subframe transmittedby each PDSCH may be applied.

Alternatively, as illustrated in FIG. 20B, in the UL subframecorresponding to the last DL subframe of a scheduling window B or the ULsubframe corresponding to the DL subframe transmitted by the lastscheduled PDSCH, an ACK/NACK for the PDSCH scheduled within thescheduling window B may be transmitted.

In the case of bundling/cross subframe scheduling of the PUSCH, a PHICHresponse may be transmitted.

In a method of FIG. 20A, in the case of operating the single cellconfiguration, the ACK/NACK for each PDSCH may be transmitted to thePUCCH format 1a/1b in the corresponding UL subframe. The ACK/NACK forthe PDSCH transmitted in the DL subframe transmitted with the PDCCH maybe transmitted as the implicit PUCCH resource, but the PDSCHstransmitted in other DL subframes are transmitted by using the explicitPUCCH resource.

The SORTD may be applied as described above. In the TDD, if mapping ofthe DL subframe transmitted with the PDCCH and the implicit PUCCHresource exists, the implicit PUCCH resource is used, and if not, theexplicit PUCCH resource is used.

When the SORTD is applied, in the assigning of the PUCCH resource, theaforementioned embodiments may be applied according to whether the PUCCHresource is an implicit resource or an explicit resource in the singleantenna port transmission.

In the case where the method of FIG. 20A is applied to the TDD 2 cellconfiguration, the plurality of DL subframes may correspond to one ULsubframe. In this case, the ACK/NACK may be transmitted by using thechannel selection.

In the case of transmitting the ACK/NACK in the UL subframe which canuse the implicit PUCCH resource corresponding to the control channelscheduled when scheduling the primary cell and the secondary cell fromthe control channels PDCCH and e-PDCCH of the primary cell, the implicitPUCCH resource is used, and in the case of transmitting the ACK/NACK inthe UL subframe which cannot use the implicit PUCCH resource, theexplicit PUCCH resource is used. The method may be applied even in thecase where the non-cross carrier scheduling is applied in the secondarycell.

For example, it is assumed that the implicit PUCCH resource may beensured from the control channel scheduling the primary cell in thespecific UL subframe. In this case, one implicit PUCCH resource or twoimplicit PUCCH resources may be used for the single antenna port. In thecase where the implicit PUCCH resource may not be ensured from thecontrol channel scheduling the secondary cell in the same UL subframe,one explicit resource indicated by the ARI or an explicit PUCCH resourceset indicated by the ARI (that is, a set of two PUCCH resourcesconfigured by the RRC or a set of one PUCCH resource configured by theRRC and a PUCCH resource applied with the offset value based on thecorresponding PUCCH resource) is used for the single antenna port.

When the SORTD is applied, in the case of ensuring the implicit resourceas the first antenna port, two or maximum four implicit resources areused from the control channel scheduling each cell, and in the case ofnot ensuring the implicit resource as the resource for the first antennaport, one pair of explicit resources (that is, two explicit PUCCHresources) indicated by the ARI may be used for the second antenna port.Alternatively, two explicit resources indicated by the ARI are used forthe first antenna port and the second antenna port, respectively.

Meanwhile, a type of FIG. 20B is an example of FDD, and in the case ofB>1, the ACK/NACK for the PDSCH of the plurality of DL subframes needsto be transmitted in one UL subframe. To this end, the PUCCH format 1busing consecutive ACK/NACK counting and the PUCCH format 1b using thechannel selection may be used. Alternatively, the PUCCH format 3 mayalso be used.

The single cell may be applied only in the case of B>1 or appliedregardless of B.

In order to notify the selection of the explicit PUCCH resource, the ARImay be transmitted and borrow the TPC. For the ARI transmission, aseparate field may be included, and particularly, in the case of thee-PDCCH, the ARI may be transmitted by using an ARO field.

In a carrier aggregation situation, the present invention may be appliedeven in the case where the PDSCH of the secondary cell is scheduled.

Which method of the methods of FIGS. 19 and 20 is used may be signaledby the base station.

Further, which method of the methods of FIGS. 20A and 20B is used may besignaled by the base station. The signaling may be broadcasted to theMIN and the SIB, configured by a UE-specific RRC, or included in the DCIformat transmitted through the PDCCH.

Further, the aforementioned methods may be applied for each site in thecase of transmitting the ACK/NACK for each site in the carrieraggregation between different sites.

<PUCCH Resources for SORTD Related to PDCCH or e-PDCCH Positioned inSecondary Cell>

In the case of configuring an implicit resource mapping relationshipbetween the DL control channel (PDCCH, e-PDCCH) positioned in thesecondary cell and the PUCCH resource of the primary cell, collision ofthe PUCCH resources between different user equipments may occur due tothe implicit resource mapping relationship between the DL controlchannel for the primary cell and the PUCCH resource of the primary cell.Accordingly, the implicit resource mapping relationship of the DL ondifferent cells and the control channel PUCCH resource is notconfigured, but explicitly assigned PUCCH resources may be used.

In the case of receiving the scheduling to the e-PDCCH on the secondarycell, the PUCCH resource required for the PUCCH format 1b using thechannel selection may use the explicitly assigned PUCCH resource. In thecase of receiving the scheduling to the PDCCH on the secondary cell, theexplicit resource configured for the PUCCH format 1b using the channelselection may be used. Since the PDSCH scheduling is performed by onlyone of the PDCCH and the e-PDCCH for the same secondary cell, there isno problem of resource collision in the explicit PUCCH resourceconfigured for each user equipment. Further, configuring a separateexplicit PUCCH resource for each of the PDCCH and the e-PDCCH may beunnecessary. A ‘n1PUCCH-AN-CS-List-r10’ value in the‘channelSelection-r10’ which is an RRC parameter may be commonly appliedeven in the case of using the e-PDCCH.

Hereinafter, the PUCCH format 1b using the channel selection is applied,and the non-cross carrier scheduling situation is assumed. In the caseof requiring one explicit resource related with the secondary cell anddirectly indicated in the single antenna port transmission and in thecase of requiring two explicit resources, when each SORTD is configured,two explicit PUCCH resources are required or a maximum of four explicitPUCCH resources may be required.

1) In the case of requiring one PUCCH resource corresponding to thesecondary cell, two explicit PUCCH resources given below may berequired.

ax: Explicit PUCCH resource for the first antenna port indicated by theARI of the scheduling PDCCH of the secondary cell,

ax′: Explicit PUCCH resource for the second antenna port received by theRRC of the scheduling PDCCH of the secondary cell

2) In the case of requiring two PUCCH resources corresponding to thesecondary cell, four explicit PUCCH resources given below may berequired.

ax: First resource of an explicit PUCCH resource set for the firstantenna port indicated by the ARI of the scheduling PDCCH of thesecondary cell

ay: Second resource of the explicit PUCCH resource set for the firstantenna port indicated by the ARI of the scheduling PDCCH of thesecondary cell

ax′: First resource of one explicit PUCCH resource set for the secondantenna port received by the RRC of the scheduling PDCCH of thesecondary cell

ay′: Second resource of one explicit PUCCH resource set for the secondantenna port received by the RRC of the scheduling PDCCH of thesecondary cell

<SORTD Resource Configuration and RRC Configuration>

When the PUCCH resource for the first antenna port in the channelselection may be implicitly obtained from the resource corresponding tothe CCE occupied y the PDCCH, any one of the following methods ofensuring the PUCCH resource for the second antenna port of the PUCCHtransmit diversity in the channel selection may be used.

1) Method of using explicit resource That is, there is a method of usinga resource explicitly assigned by the RRC regardless of the implicitresource of the first antenna port. The explicit resource may beprovided one by one to the RRC, a plurality of resources is provided tothe RRC, and one resource indicated by the ARI included in thescheduling PDCCH may be used. This may vary according to the FDD and theTDD. For example, in the TDD, the resource indicated by the ARI amongfour resources assigned by the RRC may be assigned. In the FDD, oneresource assigned by the RRC may be used.

2) Method of using implicit resource That is, a PUCCH resource applyingan offset value additionally configured in the implicit PUCCH resourceof the first antenna port may be used. The offset value may be 1 or 2.

The aforementioned methods may use an appropriate method according tothe number of user equipments accessed to the cell and traffic. Forexample, in a situation where the CCEs are insufficient, in order toensure the implicit resource, scheduling limitation may occur. In areverse case, by assigning the explicit resource for each userequipment, an uplink resource block which is usable as the PUSCH iswasted. Accordingly, two types may be configured and then selectivelyused. In this case, the two types may be cell-specifically orUE-specifically configured through broadcast/RRC/L1/L2 signaling and maybe configured by the RRC.

FIG. 21 illustrates a configuration of a base station and user equipmentaccording to the embodiment of the present invention.

The base station 100 includes a processor 110, a memory 120, and a radiofrequency (RF) unit 130. The processor 110 implements a function, aprocess, and/or a method which are proposed. For example, the memory 120is connected with the processor 120 to store various information fordriving the processor 110. The RF unit 130 is connected with theprocessor 110 to transmit and/or receive a radio signal.

UE 200 includes a processor 210, a memory 220, and an RF unit 230. Theprocessor 210 implements a function, a process, and/or a method whichare proposed. For example, the memory 210 is connected with theprocessor 220 to store various information for driving the processor210. The RF unit 230 is connected with the processor 210 to transmitand/or receive the radio signal.

The processors 110 and 210 may include an application-specificintegrated circuit (ASIC), other chipset, a logic circuit, a dataprocessing device, and/or a converter that converts a baseband signaland a radio signal to each other. The memories 120 and 220 may include aread-only memory (ROM), a random access memory (RAM0, a flash memory, amemory card, a storage medium, and/or other storage device. The RF units130 and 230 may include one or more antennas that transmit and/orreceive the radio signal. When the embodiment is implemented bysoftware, the aforementioned technique may be implemented by a module (aprocess, a function, and the like) performing the aforementionedfunction. The module may be stored in the memories 120 and 220 and maybe executed by the processors 110 and 210. The memories 120 and 220 maybe present inside or outside the processors 110 and 210 and connectedwith the processors 110 and 210 by various well-known means.

What is claimed is:
 1. A method for transmitting an uplink controlsignal of a user equipment (UE) in a wireless communication system, themethod comprising: determining at least one explicit physical uplinkcontrol channel (PUCCH) resource; and transmitting an uplink controlsignal by using the at least one explicit PUCCH resource, wherein if theUE is configured for two antenna port transmission, two explicit PUCCHresources are used to transmit an acknowledgement/not-acknowledgement(ACK/NACK) for a physical downlink shard channel (PDSCH) without acorresponding enhanced-PDCCH (e-PDCCH) and, wherein the e-PDCCH is acontrol channel positioned in a data region to which the PDSCH isassigned.
 2. The method of claim 1, wherein the PDSCH without thecorresponding e-PDCCH is a PDSCH scheduled by semi-persistentscheduling.
 3. The method of claim 2, wherein the PDSCH without thecorresponding e-PDCCH is received through a primary cell.
 4. The methodof claim 1, wherein the two explicit PUCCH resources are spatiallyorthogonal from each other.
 5. The method of claim 1, wherein, in a timedomain, the data region is located after a control region in which aphysical downlink control channel (PDCCH) is received.
 6. User equipment(UE), comprising: a radio frequency (RF) unit which transmits orreceives a radio signal; and a processor connected with the RF unit,wherein the processor determines an explicit physical uplink controlchannel (PUCCH) resource and transmits an uplink control signal by usingthe explicit PUCCH resource, wherein the explicit PUCCH resource is usedto transmit an acknowledgement/not-acknowledgement (ACK/NACK) for aphysical downlink shard channel (PDSCH) without a correspondingenhanced-PDCCH (e-PDCCH) and wherein the e-PDCCH is a control channelpositioned in a data region to which the PDSCH is assigned.
 7. The UE ofclaim 6, wherein the PDSCH without the corresponding e-PDCCH is a PDSCHscheduled by semi-persistent scheduling.
 8. The UE of claim 7, whereinthe PDSCH without the corresponding e-PDCCH is received through aprimary cell.
 9. The UE of claim 6, wherein the two explicit PUCCHresources are spatially orthogonal from each other.
 10. The method ofclaim 6, wherein, in a time domain, the data region is located after acontrol region in which a physical downlink control channel (PDCCH) isreceived.